(A Big Finish audio adventure. This story is a must own for Cybermen fans!)

The Doctor and Charley are taking Ramsay, a vortesaur, back to his home in the Space-Time vortex using the Tardis. However, Ramsay has fallen ill and the Doctor is worried the shock of reentering the vortex may kill him. Not knowing much about vortesaur physiology, the Doctor decides to try to find more information on treating Ramsay's condition.

Two smugglers, Thinnes and Digly, are on a mission for their boss Grash. While preparing their spacesuits, they are interrupted by a Garazone Space Patrol vessel curious about their presence in a junking zone for space debris. Thinnes claims their ship, the cargo loader Silver Jackal, has experienced an engine malfunction and that repairs are being completed. Accepting the explanation, the Space Patrol moves on. The Silver Jackal proceeds to search the sector, until Digly detects their target: a derelict star destroyer. The airlock hatch on the Destroyer is too large for the Silver Jackal's connector, so Thinnes decides the two of them will don their spacesuits and spacewalk over to the ship. Digly is not happy as the prospect.

Upon entering the destroyer, they find the ship is still pressurized, but with a stench in the air. Thinnes plans to scavenge the ship's weapons systems and sell them to fighters in the Orion War for a large profit. As they search the ship, banging noises can be heard in the distance. Digly is alarmed at the noise, but Thinnes claims that all spaceships make these kinds of noises. The noise grows closer, and a figure appears out of the shadows. Digly and Thinnes open fire with their sidearms, but their weapons are useless. The two try to run, but the figure hunts them down and kills them.

The Doctor and Charley arrive at Garazone Central, a giant city floating in space that is infamous for its merchants and smugglers. Exploring the Garazone Bazaar, Charley attempts to locate help for Ramsay. Instead, all she gets is the attention of an overly amorous merchant. Relocating the Doctor, the two explore a promising looking shop. The Doctor recognizes the shopkeeper, Ike, as a moonlighting member of the Space Merchant Corps that he saw at the spacedocks. Figuring that Ike may be trouble, the Doctor leads Ike to believe that Charley and he are government inspectors.

Nervous, Ike excuses himself and heads to the back room. Ike uses a communicator to contact Grash. He tells Grash he has two suspicious people in his shop and that he's nervous, given the disappearance of the Silver Jackal. Grash tells him not to worry about the Doctor and Charley, but that Ike must get back their salvage ship, the Vanguard. The regular captain has been replaced, and the new captain has moved up the departure time.

While exploring the shop, Charley comes across a gold plated Cyberman head. The Doctor explains that it a relic from the Cyber War, which was fought in the distant past. In the current time, the Cybermen are still entombed on Telos. As they are talking, Ike slips out of the shop. Charley is worried he may be after the Tardis, located in the spacedocks. The Doctor decides they should play it safe and use a gravpad to try and beat Ike back to the docks. He has Charley grab a promising medical book for Ramsay before they leave.

Navigator Vol is loading supplies into the Vanguard. He is preparing to take inventory when Captain Deeva Jansen issues a command override, and informs him the ship is to be ready for launch in ten minutes.

Charley is amazed at her gravpad, which uses an antigrav propulsion system. As she and the Doctor travel trough Garazone Central, they are caught in a "rain storm", which is actually condensation build up from the city's air conditioning systems. As they approach the spacedocks, the gravpads start to short out and the force fields destabilize.

Vol is hurrying to finish loading the supplies before launch. He is also worried that Ike won't make the departure time, and he knows the captain won't hold the ship. The Vanguard's launch bell begins sounding.

The Doctor and Charley have a rough landing at the docks. They arrive in time to see the Tardis being loaded into the Vanguard's cargo hold. Unable to find help in time, the Doctor and Charley sneak aboard the ship using the sonic screwdriver.

Ike, who is the ship's pilot, just makes it on to the Vanguard before launch. Vol wants to wait for Ike to reach the flightdeck before launching, but Captain Jansen decides to pilot the ship out herself. As Ike arrives, the captain tells him he will be on report.

The Doctor and Charley are in the Vanguard's waste bay. The Doctor is hoping to avoid a run in with the crew, so the two set out to find the Tardis and quickly leave. The Doctor can tell from the vibration of the bulkheads that the ship has gone to hyperdrive. He is puzzled as to why a salvage ship would be in such a hurry.

Ike is annoyed with the new captain, but Vol warns him to watch himself. The captain doesn't seem fond of the crew and also carries a custom sidearm, which Vol believes the captain wouldn't hesitate to use. The two are suspicious of Jansen and believe something must be going on of which they are uninformed. To them, she seems out of place on a salvage ship.

The Vanguard's proximity alarm sounds. Vol orders Ike to cut the ship's hyperspace engines. The Vanguard is on a collision course with the abandoned star destroyer. Captain Jansen storms on to the flight deck to demand an explanation for the engine stop, then berates the crew for not spotting the derelict ship earlier. She orders them to set the navigation system for emergency maneuvers, but the thrusters on the old salvage ship are not responding. Deeva Jansen orders them to try to restart the hyperdrive, a very dangerous risk so soon after shutting them down.

The Doctor is alarmed at the sudden shut off of the Vanguard's hyperdrive, and he and Charley quickly locate the cargo hold carrying the Tardis. Upon getting inside, the Doctor ties the Tardis sensors to those of the Vanguard, so he can see what is happening to the ship. The image of the star destroyer appears on the screen, giving Charley an uneasy feeling. Realizing a collision is immanent, the Doctor sets the Tardis in motion.

The Vanguard's hyperdrive has reinitialized, and Captain Jansen orders it set in reverse for a three nanosecond burst. The crew is highly nervous about the order, but Deeva Jansen will not back down.

The Tardis unexpectedly rematerializes. Checking his sensors, the Doctor realizes the Vanguard activated its hyperdrive and the Tardis was caught in the resulting warp field. This has caused a buildup of temporal energy in the Tardis, a highly dangerous situation. The Doctor and Charley need to flee the Tardis, though Ramsay can be left behind, as he feeds on temporal energy. The Doctor grabs a temporal energy tracker so they can monitor the energy levels inside the Tardis, then he and Charley make a quick exit.

Upon existing the Tardis, Charley realizes they are no longer in the cargo hold of the Vanguard. The air is cold and a stench fills the air. The Doctor believes they have landed on the derelict star destroyer. To keep warm until they can reenter the Tardis, the Doctor suggests a walk through the ship.

Ike and Vol notice on the flightdeck's monitors that the airlock on the ship has yet to be opened. They expect Grash, leader of the recon team, and the rest of his group are arguing with the captain over having to perform a spacewalk.

The Vanguard's connector will not fit the star destroyer's airlock hatch, so Grash feels the mission should be terminated. He argues the ship is too dangerous and too large to scrap. Deeva Jansen offers the crew double bonuses if they will continue on with the mission. Grash reluctantly agrees.

Ike hacks into the flightdeck's command computer, looking for information on the old star destroyer. He discovers a Space Patrol report documenting the sighting of the Silver Jackal in the area. Before he can get any further, a security block activates in the computer, which can only broken from the central terminal. Deeva Jansen enters the room and catches Ike in the act. She warms him that his hobby may prove very dangerous to himself.

The Doctor and Charley find the star destroyer's control room. The room is very sparse and bare, with fixtures designed for very large people. The ship has also undergone a total systems shutdown. Charley hears a noise in the distance.

Grash and his team, Chev and Kelsey, have entered the star destroyer through the airlock. A sensor check reveals an breathable atmosphere, though when they remove their helmets they are greeted with a rancid smell. Grash, Chev, and Kelsey split up to explore the ship.

The Doctor suspects the noise was either someone entering the ship from the Vanguard, or perhaps the sound of something waking up. A light begins to flash on a control panel. The Doctor feels they have seen enough and suggests a hasty return to the Tardis to check the temporal energy levels.

Kelsey and Chev can both hear something moving through the ship towards Kelsey's position. Kelsey is getting nervous, and rounds a corner to stumble directly into the Tardis.

The Doctor and Charley are trying to find their way back to the Tardis, when they also hear something moving.

Kelsey doesn't believe the sounds he heard were coming from the Tardis. Grash tells Kelsey to keep his gun handy anyway, and that he and Chev are on their way. A figure moves out of the darkness and attacks Kelsey.

The Doctor hears the attack and he and Charley rush to help.

Captain Jansen tries to raise the recon team on the communicator. Grash gets through and tells her that Kelsey is in trouble and the recon team may need backup. Jansen tells Ike to suit up and be ready to head to the star destroyer.

The Doctor and Charley discover both the Tardis and Kelsey. Examining the body, the Doctor finds a faint pulse while Charley tries to stop the bleeding. The Doctor recognizes Kelsey's uniform as that of the Merchant Space Corps, and believes his attacker must have been very strong and possibly deranged. The attacker is also most likely still in the area. The Doctor and Charley hear approaching footsteps.

Chev arrives on the scene to find the Doctor and Charley over Kelsey's body. She is in shock, but the Doctor tells her that Kelsey must be take to a hospital immediately. Grash appears soon after and draws his gun on the Doctor. Grash contacts the Vanguard and informs the captain that he has found Kelsey and also his murderers. The Doctor and Charley protest their innocence and tell Grash that Kelsey is still alive, though barely. Deeva Jansen tells Grash to patch in his suit cam over to the Vanguard so she can see what is going on. Grash wants to execute the Doctor and Charley on the spot, but the captain orders the two brought back to the Vanguard. Ike will bring spare spacesuits over to the star destroyer for the journey.

The Doctor, Charley, and the recon party return to the Vanguard. Captain Jansen orders Ike and Chev to take the now dead Kelsey to the sickbay. She then begins interrogating the Doctor. Vol interrupts on the intercom and informs the captain that an unknown transmission is being broadcast from their location, airlock reception. Grash searches the Doctor and finds his sonic screwdriver and tracking device, which Deeva Jansen promptly confiscates. However, neither is the source of the transmission. The Doctor then sees something small dart across the deck, but is unable to get a good look at it. Vol calls again to say the transmission source is on the move. The Doctor spots scratch mark leading from the airlock to where he saw the movement. Captain Jansen is still suspicious of the Doctor and Charley, but she believes that are not strong enough to have been Kelsey's attackers. Grash suggests they may be androids fleeing the Orion War, but Deeva Jansen is certain no androids exist outside of that system. Suddenly, the airlock and surrounding areas begin to lose power. The captain contacts Vol on the flightdeck, but he is unable to provide an explanation and the emergency batteries are unable to compensate.

Chev and Ike deliver Kelsey's body to the sickbay. The sickbay begins to lose power. Ike contacts Vol, who says the power failures are spreading throughout the ship. Vol contacts the captain with the bad news, but still has no explanation. Communications then fail.

The Doctor asks Jansen if the power systems can be accessed nearby. The captain says there are several maintenance hatches in the area and agrees to take the Doctor to the nearest one. They discover a hole burned into the hatch and more scratch marks on the deck. Captain Jansen agrees to return the Doctor's sonic screwdriver so he can use it as a torch, then unlocks the hatch. The main power cables have been burned through by some sort of energy beam, but the life support systems were deliberately left untouched. The expanding power failures appear to be the result of the intruder continuing its sabotage as it moves through the Vanguard. The captain orders everyone to report to the flightdeck.

Vol is unable to track the intruders progress through the ship, as the security systems no longer have power. Chev is indignant at seeing the Doctor and Charley on the flightdeck, as she still believes the two were Kelsey's attackers. To show that they mean no harm, the Doctor offers to help track down the intruder. He asks the recon crew, who are still wearing their spacesuits, to turn around so he can examine their backpacks. On Grash's pack the Doctor finds the same type of scratch marks found on the decks. The Doctor believes the intruder hitched a ride from the star destroyer over to the Vanguard, then slipped off at the first convenient moment. To find it, the Doctor suggests cutting off life support to some areas of the ship, then using that power to run the the security system. Deeva Jansen sends the Doctor, Vol and Chev out to execute the plan, but insists Charley remain as her prisoner to ensure the Doctor does not try any tricks. While talking to the captain and Grash, Charley accidentally lets it slip that she and the Doctor have a ship on the star destroyer. Grash wants to call the Space Patrol to investigate the ongoings, but Captain Jansen decides the crew can handle the situation on their own.

The Doctor and Vol are working on rerouting power while Chev stands guard. Trying to appease the still suspicious Chev, the Doctor insists that he and Charley were merely exploring the star destroyer and that their transport is still over there. Finally the security systems are reactivated, and Vol detects a transmission being sent from the stern of the ship.

Ike and Grash are monitoring the now active security system from the flightdeck and also detect the transmission. The Doctor and the rest of his party arrive, where he is informed the transmission is being beamed back to the star destroyer. The Doctor feels the best course of action would be to return to the star destroyer and see who or what is receiving the transmissions. Deeva Jansen agrees to the plan, but insists Charley remain on the Vanguard so that the Doctor doesn't attempt an escape. Grash refuses to go along with the captain and declares her unfit for duty, taking command of the Vanguard by force. The crew attempts to power up the ship's thrusters and depart, but the Vanguard suffers an engine failure. As the ship is stranded, Grash agrees to let the Doctor and Deeva Jansen explore the star destroyer. However, he will leave as soon as repairs are made, regardless of whether the Doctor and the captain have returned.

The Doctor and Deeva Jansen arrive on the star destroyer. Curious about why she has made the trip over, the Doctor begins to question her about her motives. A noise can be heard in the distance. The Doctor is sure it must be Kelsey's attacker.

Ike informs Grash and Chev that the Doctor and Charley were the visitors to his shop earlier. None of them are sure why the Doctor has not yet revealed their illegal activities to Captain Deeva Jansen. However, Grash is worried their operations may be in jeopardy. Grash tells Ike and Vol to retrieve Charley from the quartermaster's office and take her down to the engine room. They are to use Charley as bait to flush out the intruder, then begin repairs once the intruder has been eliminated.

The Doctor and Deeva Jansen are attacked by a deranged Cyberman. A few quick shots to its chest unit from Jansen's gun are enough to disable it. The Doctor is surprised that a scrap ship captain recognizes a supposedly extinct Cyberman, but Deeva Jansen claims to have studied military history at her university. The Doctor removes the Cyberman's face plate to study its neural network, and discovers the Cyberman is receiving transmissions. The Doctor realizes the Vanguard's intruder must be a Cybermat.

Ike and Vol, their weapons drawn, send Charley ahead of them into the engine room. Protesting to Vol, who is unaware of Ike and the others' illegal activities, Charley states that the only reason she is being sent into the room is because she knows about Ike's smuggling operation. Vol is unhappy about the revelation, but Ike threatens to send him into the engine room with Charley if Vol says anything.

Examining the Cyberman, the Doctor concludes it was subjected to some sort of freezing, perhaps the same kind used on Telos. However, the Cybermen appears to be the victim of a refrigeration malfunction, reactivating it a damaged state. This indicates that the Cybermat did not activate the Cyberman, and that other Cybermen must be frozen on the ship as well. The Doctor Jansen decide they must find the other Cybermen and ensure that none of them are revived.

Within the star destroyer, three Cybermen are attempting to revive their leader.

Due to a system fault, the Cybermen are unable to revive their leader. One Cyberman will begin repairs while the other two will proceed over to the Vanguard.

Searching the Vanguard's engine room, Charley comes face to face with the Cybermat.

The Doctor and Captain Jansen detect a large chamber in the ship, but are unable to activate a bulkhead door that stands in their way. The door has shorted out, which Jansen believes may have been a result of one of the ion storms that often plague the Garazone Sector. It would also explain the malfunctioning refrigeration system. Jansen suggests they force the door, which the Doctor knows would take quite a bit of strength.

The Cybermat merely stares at Charley, perhaps awaiting new orders, while Ike advises Grash of the situation. None of them have seen a Cybermat before, and they are unaware of what it is. Grash says to let the Cybermat kill Charley, then Ike can destroy the intruder. If the Cybermat fails to fire first, Ike is to kill Charley and make it look like the Cybermat was responsible. Though a criminal, Ike is unwilling to commit murder. Charley tells them to quit talking and do something.

Deeva Jansen has forced the door open, and she and the Doctor enter the chamber. They are greeted by the stench of death.

Vol shoots the head of Cybermat off, much to Ike's annoyance. Though disabled, the Cybermat has already done so much damage to the engines that repairs are impossible. Grash and Chev call Ike for an update, and learn that Charley is still alive. An alarm sounds on the flightdeck that someone is attempting to open the outer airlock. Grash believes it to be the Doctor and Captain Jansen, who he was hoping to charge with desertion of her position. Unable to secure the airlock from the flight deck, Grash and Chev move to intercept them in person.

The Doctor and Captain Jansen find a room full of corpses, all at various stages of cyber-converstion. Deeva Jansen appears to be quite knowledgeable about the Cybermen, but avoids the Doctor's questions about the source of her information. The corpses were prisoners, and the star destroyer was a factory ship for building new Cybermen. The assembly line was damaged by the ion storm, leaving the victims to suffer a painful death and their remaining human elements to rot away. The Cybermen captors had placed themselves in hibernation and attempted to ride out the storm. Deeva Jansen detects another chamber beyond, and she and the Doctor head out to investigate.

Grash and Chev await outside the airlock door for what they believe to be Captain Jansen and the Doctor. As the door opens, they instead find themselves in the presence of two Cybermen. Grash and Chev open fire, but their weapons are useless. As they attempt to flee, Grash is struck down by an energy beam. Chev is allowed to escape, so the Cybermen can follow her to the other crew members.

Captain Jansen detects an energy discharge and she and the Doctor witness the third Cyberman reactivating the Cyberleader. When the Cyberleader is informed of the Vanguard's presence, he orders the crew to be captured and cyber-converted. Other Cybermen have already been activated, and the Cyberleader directs the revival process to continue. The Doctor suggests to Jansen that the two of them leave now and attempt to reach the Tardis.

Charley and Vol are examining the remains of the Cybermat, which is still somewhat active. Ike attempts to repair the engine, but has no luck. Chev runs into the room and tells the group that something has boarded the ship and killed Grash.

The Cybermen manage to reactivate the star destroyer's security system, detecting the Doctor and Jansen. The Cyberleader orders their capture. Captain Jansen is using a tracker to find the Tardis and comments on the unusual readings coming from it. The Doctor offers to tell her more in exchange for his own tracker, but Jansen refuses to return it.

Chev, Ike, Vol, and Charley are discussing how the Cybermen must have been responsible for Kelsey's murder and the sabotage on the Vanguard. Chev is hoping to seal the engine room off for defense, but there is not enough power. Footsteps are heard coming down the hallway and the group readies for an attack. However, it is not the Cybermen, but a wounded Grash.

As they walk, the Doctor comments to Jansen that the Cybermen are only reactivating each other one at a time, rather than in groups. Captain Jansen thinks maybe it is an emergency measure, and that the main systems may still be damaged. Jansen's tracker begins to detect movement coming towards their position. It is the Cybermen. The path to the Tardis is blocked, so the Doctor and Deeva Jansen make a run for the airlock as the Cybermen open fire.

A Cyberman informs the Cyberleader that the humanoids have been spotted. The Cyberleader orders their capture before they can reach the airlock.

Deeva Jansen and the Doctor are being chased through the star destroyer by the Cybermen. Reaching the airlock just ahead of their pursuers, the two of them replace their helmets and escape into space.

Grash wants everyone in the engine room to return with him to the airlock. His voice sounding odd, he informs them that he has killed the two Cybermen, but more are on the way. They should return to the airlock to prepare a defense.

The Doctor and Captain Jansen reach the Vanguard's outer airlock door. However, no Cybermen are pursuing, which the Doctor finds strange.

The Cyberleader is informed that the Doctor and Jansen have reached the Vanguard. The Cybermen there will be waiting for them.

As Deeva Jansen opens the inner door of the airlock, she and the Doctor come face to face with the two Cybermen. Jansen quickly dispatches them with her gun. Just then, Chev, Charley, and everyone else from the engine room arrive. Grash collapses on to the deck out cold. Deeva Jansen reclaims her position as captain of the Vanguard. The Doctor informs the crew about the Cybermen and what lies over in the star destroyer. Captain Jansen orders Chev and Ike to take Grash to his cabin, while Vol is to jam the airlock mechanism. Afterwards Vol is to escort the Doctor and Charley to the flightdeck. Jansen has some business to take care of, then she will meet them there.

A cyber-force has been reactivated, and the Cyberleader orders them to the Vanguard to capture the crew. A Cyberman informs the Cyberleader that contact can be reestablished with the damaged Cybermat. Its offensive capabilities have been destroyed, but it can be programmed with new instructions.

Vol warns the Doctor and Charley to be careful around Ike and Grash, given their criminal activities, but the Doctor feels its of little concern given the current situation. Ike and Chev enter the flightdeck and overhear the conversation. The Doctor informs Ike that his criminal activity is of no interest to him or Charley. All the Doctor wants is information, especially about Captain Deeva Jansen. Vol performs a security scan, showing Jansen to be in the computer command module. The Doctor asks the crew to tell him about her.

Captain Jansen is searching the computer database for information on the Doctor and the Tardis.

The crew knows very little about Captain Jansen. However, they feel the captain looks out of place on a salvage ship. The Doctor also notices that her gun is unique, and it seems to have been designed specifically for fighting Cybermen. While the other crew members' weapons seem ineffective, Deeva Jansen can destroy a Cyberman with one shot. The Doctor asks Ike for help in hacking into the ship's database so he can find more information. Suddenly, an alarm sounds that someone is trying to enter the airlock. The Doctor tell Ike to call the captain for her gun, while he and the others head for the airlock.

Captain Jansen's search reveals that the Doctor has been seen in various time periods, and that he has interacted with the Cybermen on several occasions. The computer believes the Doctor would have specialist knowledge about the Cybermen. This intrigues Jansen. Just then, Ike breaks through on the communicator and informs the captain that Cybermen are attempting to enter the ship and that her gun is needed at the airlock. She informs him that she is on her way.

Clanging sounds are heard within the airlock. The Doctor has Vol open an observation port so he can see what the Cybermen are doing. There are too many of them to fight with Captain Jansen's lone effective gun. The Doctor finds the emergency controls for the airlock and decides to blow the airlock's outer doors. This way, the Cybermen will be unable to open the inner doors without depressurizing the whole ship. Though the Cybermen could survive, the crew would die before the Cybermen could capture them. Charley is alarmed that this will prevent her and the Doctor from being able to return to the Tardis, but there is no other choice. The doors are blown, and the Cybermen stop their activity in the airlock, waiting for new orders. The Doctor decides it is time for a tea break.

The Cyberleader is informed of the situation at the airlock. He orders the Cybermat to be contacted and given new instructions. The Cybermen have another plan.

The Vanguard doesn't stock any tea, but Ike offers the Doctor and Charley "G-Fresh" patches. They decide to pass. Captain Jansen calls Vol at the airlock for an update. The Cybermen are just watching Vol through the observation port. Chev has gone to check on Grash in his quarters. The captain leaves orders that she is to be contacted if the situation changes. Charley is puzzled at Grash's fainting spell, and why he claimed to have killed the Cybermen when in fact they were still alive. The Doctor realizes Grash was under cyber-control, and that Grash was attempting to lead the other crew members into a trap.

The Cybermen reestablish control over Grash using the damaged Cybermat.

Chev enters Grash's quarters, but he is no longer there. The Captain raises Chev on the communicator and explains the situation with Grash. Ike detects movement towards the airlock on the security system and contacts Vol. The captain gives Chev orders to tail Grash, then heads to the airlock herself. The Doctor notices Deeva Jansen seems in her element with these types of situations. He asks Ike for a look at the command access only computer file.

The Cyberleader is informed that Cybermat is transmitting schematics of the Vanguard. Analysis of the data show that by sealing off the hatches to airlock reception, a secondary airlock can be built. The plans are relayed to Grash through the Cybermat.

Chev is unable to locate Grash, but feels that she is being followed. The captain gets into position near the airlock.

The Doctor Ike, and Charley hack into the computer and find a Space Patrol report on the Silver Jackal. It was found adrift in space near the star destroyer, with the crew missing. The report was forwarded to military intelligence. The rest of the file is sealed by Tellurian Security, Orion Classification D-7. Charley is curious about just what is the Orion War, and what it has to do with androids. Ike tells her there are no androids outside of the Orion System.

Chev is looking for Grash, sees something move, and then is hit by an energy beam.

The Doctor and Charley are discussing the Orion War with Ike. Enslaved androids rebelled against the humans, demanding to be treated as equals. Riots took place and androids were outlawed. During the fighting, many people were accidentally killed by the military, as it was difficult to tell androids and humans apart. The remaining androids fled to the Orion System and set up their own government. Humans in the system had to accept androids as equals, or they were forced out. This started the war between humans and androids, a war which neither side has been able to win in eight years. As they are talking, the Doctor spots something moving in space through the main view port, but is unable to identify it before it is gone. The Doctor asks Ike to show him on the security systems where the computer command module is, as he thinks Deeva Jansen is up to something. He believes she knew the star destroyer was a Cybermen ship, but needs computer access to figure out her plans. The Doctor heads for the module.

Captain Jansen contacts the flightdeck, as she has been unable to link up with Chev. Ike reports the security system shows two individuals headed in the captain's direction. He also is detecting a transmission coming from the Vanguard again. The captain then calls Vol at the airlock. He states that the Cybermen have attached some equipment to the other side of the airlock door. Deeva Jansen realizes the Cybermen are trying to create a secondary airlock. She orders Vol to evacuate and head for her position.

The Cyberleader is informed that there are now two humans under cyber-control. He orders the attack party to enter the Vanguard as soon as the new airlock is ready.

The Doctor and Charley reach the computer command module and open it using the sonic screwdriver.

Captain Jansen locates Vol, then contacts the flightdeck to tell the Doctor to take a gun and come to her position. Ike informs her that the Doctor has wandered off. Deeva Jansen has a suspicion of where the Doctor has gone, so she tells Vol to wait while she retrieves the Doctor.

Vol is started by Chev. She tells him that she has found something, and wants Vol to take a look. Vol is nervous about disobeying the captain's orders, but agrees to take a look. Chev shows him the Cybermat, which emits an energy beam at him.

The secure computer recognizes the Doctor from Deeva Jansen's inquiries. The Doctor uses this to confuse the computer and gain access to the classified files. They relate to the mission code named "Sword of Orion". Earth security operative CGH5/142 was to replace the deceased scrap ship captain, Deeva Jansen. She was to take command of the Vanguard and locate the derelict star destroyer. The star destroyer was suspected of carrying hibernating Cybermen, who would reactive when humanoids were present. The operative was to determine the military value of the Cybermen in order to... Before they can finish, the Doctor and Charley are interrupted by the woman known as Deeva Jansen. Deeva says the reports contain several mentions of the Doctor and she wants to know who or what he is. The Doctor refuses to help her recruit the Cybermen for Earth's cause. Ike interrupts on the intercom and informs the captain that Cybermen are boarding the ship. It appears Vol, Grash, and Chev are letting them in. The captain tells Ike to put on a spacesuit, and that she, the Doctor, and Charley will be there soon.

The Cybermen have entered the Vanguard. Vol, Grash, and Chev are ordered to put on spacesuits and return to the star destroyer. The Cybermen will search the Vanguard for the remaining humans.

The Doctor and Charley are arguing with Captain Jansen over her mission as they race to the flightdeck. As he is suiting up, Ike spots something outside the viewport moving through space. The door opens and he turns expecting the Doctor and the others, but it is a Cyberman. Before it can capture Ike, Captain Jansen appears and destroys the Cyberman. However, more Cybermen are working their way to the flightdeck. Deeva Jansen orders everyone to put one spacesuits. She then shoots out the viewport, depressurizing the room.

Cyber-command detects the explosion on the Vanguard. The Cyberleader expects the crew has been blown into space, but the Cybermen's sensors cannot detect them. They are suffering from external interference. The Cyberleader orders all Cybermen back to the star destroyer. He knows any human survivors will need to board the destroyer before their air supply runs out. The Cyberleader then orders the cyber-conversion chamber reactivated.

As the group floats over to the star destroyer, Ike spots movement again out in space. It is an approaching ion storm. Though dangerous, it will protect the Vanguard survivors from the Cybermen's sensors.

The Cybermen are now detecting the oncoming ion storm. It is of the same size and intensity of the storm that crippled their ship. The Cyberleader orders the cyber-conversion of the humans before the storm arrives. However, all the security scanners have been rendered useless due to the interference from the storm, so they cannot detect the free humans. Chev, Grash and Vol are placed in the cyber-conversion chamber, then released from cyber-control. Back in control of their minds, the three begin to panic. The conversion process is started, and they scream out in pain.

Deeva Jansen forces open the airlock on the star destroyer. The group is worried about an alarm, but their air supply is running low. They are captured by a squad of Cybermen once inside. Jansen reveals the Doctor's identity to the Cybermen, and insists they take her to the Cyberleader so she can offer him a proposition.

The Cyberleader is pleased to have the Doctor as his captive. He will take the Doctor to Telos for brain analysis. When the ship arrives, the hibernating Cybermen on Telos will be reactivated, creating a a new Cybermen army. The Doctor taunts the Cyberleader that his ship is too damaged to make the trip back, though the Cyberleader is confident he will find a way. Deeva Jansen then offers him help through an alliance.

The initial phase of cyber-conversion has been completed on Chev, Grash and Vol. The second phase, implantation of the cyber-neural network, begins. Once again their suffering is intense. Grash's emotions are too erratic for a successful conversion, so he is terminated by the Cybermen.

Deeva Jansen has been authorized to have the Cybermen's ship repaired if they will form an alliance with humanity against the androids. Charley and the Doctor begin to argue with Ike and Jansen, saying that the androids should be treated with respect by humans and that the war is unjust. Captain Jansen is surprised that the two of them would be android sympathizers. The Cyberleader considers a moral discussion to be irrelevant. He orders everyone taken to the cyber-conversion chamber, except for the Doctor who is to be frozen. He has no interest in Deeva Jansen's preposition. The Doctor offers a counter proposition. He will use power from the Tardis to construct an energy shield around the star destroyer, protecting it from the ion storm. In return, he, Charley, and the Vanguard's crew are to be freed. Just then, the ship is hit by the beginning of the storm. The Cyberleader agrees to the Doctors terms and orders the humans released. Jansen quickly grabs her gun and opens fire on the Cybermen. Ike is recaptured, but Jansen, the Doctor and Charley escape. However, Jansen is wounded in the fire fight.

The Cybermen are diverting all their power to emergency shields, but it will most likely not be enough. The Cyberleader orders Ike taken to the cyber-conversion chamber.

The Doctor, Charley, and Jansen reach the Tardis, but Jansen's wounds are bad. The Doctor tries to examine her, but Jansen pushes him away. Jansen in not human, but an android. The offer of an alliance. With the Cybermen was merely a ruse to stall for time. Her true mission for Earth was to obtain details of the cyber-conversion process, which are now stored in her memory banks. The human military wants to build their own cybernetic troops to fight the androids. However, Deeva Jansen is a double agent, and she will be giving her information to the androids. They plan to cyber-convert their human prisoners of war. The storm buffeting the star destroyer intensifies, and the three must leave immediately. The Doctor is willing to transport Deeva Jansen, but only if she wipes her memory of the cyber-conversion process. Jansen agrees.

As the Doctor and Charley help Captain Jansen to the Tardis, Cybermen arrive on the scene. Jansen cannot reach her gun, and the Cyberleader threatens to dismember Charley if the Doctor does not agree to transport the Cybermen to Telos in the Tardis. Suddenly. a hull breach occurs. The Doctor gets his helmet on, but is ejected out into the storm. Charley is not able to reach her helmet and begins to suffocate. The Doctor blacks out.

The Doctor awakens to Charley shaking him. The two are floating in space, surrounded by the debris of the star destroyer and helpless Cybermen. Deeva Jansen is nowhere to be seen. She had given her life support pack to Charley before the ship disintegrated. The Doctor and Charley find the Tardis, where the Doctor begins scanning for Deeva Jansen. Androids do not need air, but the her systems would have frozen in space. He is unsuccessful. The Doctor wonders if Jansen will ever be found and reactivated. He sets the Tardis in motion and goes to make a cup of tea.