TIME LORDS AND TIME TRAVEL

The Time Lords, the ruling elite of the planet of Gallifrey, are the undoubted masters of time travel in the DOCTOR WHO universe, yet even they do not understand all of its intricacies. Great pioneers such as Rassilon and Omega have mastered elements of it and passed on the benefits of their knowledge and achievements to their successors. Armed with this knowledge, the Time Lords have established themselves as invigilators of the laws of time, their own regulations about what can and cannot be done to the fabric of time and space.

Headed by the High Council of Time Lords, which is led by the president, Gallifreyan society has stagnated. A strict policy of non-interference in the affairs of the universe has turned the Time Lords from innovators into mere observers and preservers of the balance of time. If they intercede it is only to correct an abuse of the laws of time, but even then they prefer to use a free agent, such as the Doctor, to do their dirty work.

The High Council consists of the president, chancellor, castellan and the cardinals of Gallifrey's Academy. The president is the figurehead of Gallifreyan society and has wide-ranging powers. His badges of office are the Sash of Rassilon, an ornate, wide segmented band of gold-coloured metal reputedly with the power to protect its wearer against even a black hole; the Rod of Rassilon, which allows access to the energies of the black hole that provides Gallifrey with its power; and the Coronet of Rassilon, which enables the wearer to gain access to the matrix.

The chancellor is, in effect, the president's conscience; in a way he is more powerful because he sees that the president's wishes are fulfilled. He secretly guards the Great Key of Rassilon from the president so that the powers of Rassilon can never again be wielded by one individual. The chancellor's badge of office, an oval gold medallion on a chain, is also a personal force field (Strength 10) that can be extended to protect one other person next to the chancellor.

Security is the main concern of the castellan, who has the forces of the Citadel Guard at his disposal as well as an extensive network of surveillance cameras. He is also responsible for the maintenance of the transduction barrier, a great force field that protects Gallifrey from attack. Citadel Guards are distinctively dressed in red tunics trimmed with white, red trousers tucked into red leather boots, white cloaks, and red dome-shaped helmets. Officers additionally wear a silver-coloured breastplate to denote their rank. Each guard is armed with a staser, a low-powered blaster that inflicts 6 Wounds on kill and 3 Wounds on stun. A section of the Citadel Guard is under the direct control of the president.

Within the Citadel, the city of the Time Lords, life is very much devoted to introspective studies at the Academy, Gallifrey's centre of learning. The Academy comprises three colleges -- Prydon, Arcalia and Patrex -- at which young Time Lords receive a thorough education into the history and nature of the universe. Academic life, however, is anathema to some Time Lords, who become renegades: the Doctor, the Master and the Meddling Monk are among those that wander through time and space; other Time Lords have left the Citadel to become close to nature, and prefer to live rough in the wilds of Gallifrey.

The amplified panatropic computations network, commonly known as the matrix, typifies Time Lord stagnation. It is the electronic memory used to record and preserve the experiences of all Time Lords; it contains details and the mind prints of every Time Lord except those, such as the Master, who are clever enough to erase their patterns. A Time Lord can be connected to the matrix, allowing him to enter it as a virtual reality; if more than one mind is connected at a time, the weaker one will be subjected to the reality imposed by the other.

Time And Time Travel

Time is a flexible medium. Mason's temporal analysis compares it to an elastic membrane that will yield if pushed, but will spring back once its limits are reached to return to equilibrium. The effect is to propel the affected sector of space and time back to the point at which interference began: time, quite simply, catches up with the meddlers. The consequences of becoming caught in the temporal inrush are a matter of conjecture, but it is suspected that extreme ageing of those alien to the time and space would occur -- a fatal effect over a period of several centuries! It is possible extensively to deform the temporal membrane only by pushing against different parts of it, in effect spreading the load.

It would be easy to abuse the ability to travel freely in time, and part of the reason why the Time Lords seldom do so is out of a sense of responsibility. Instead they vigorously police time travel to put a stop to infringements of the laws of time. If they travel, they do so in TARDISes, sophisticated time machines that are virtually self-sufficient micro-universes.

The most important regulations governing time travel are the first and second laws of time and the Blinovitch limitation effect. The first law of time simply states that no one should be allowed to meet themselves. The law has been broken on several occasions: the Doctor has been permitted by the Time Lords to meet other incarnations of himself; the Brigadier met himself in Mawdryn Undead, with traumatic consequences.

Blinovitch's limitation effect is a simple observation that it proves impossible to keep going back to the same point in time in order to have a second, third or even fourth attempt at getting something right or averting a catastrophe. It combines with the first law of time to prevent temporal mishaps. It first manifests as temporal and spatial displacement from the intended time zone, and in its ultimate form becomes a time loop.

In addition, the second law of time states that no one can interfere with their time line, the measure of relative continuity. This prevents a time traveller, say, going back to kill his father at a time before the traveller was born. If he were to do so, then logically he would never have existed and his father could not be killed by his hand. Anyone's time line diverges from their ancestors' time lines only at the point of birth, and until then is dependent on them. The second law of time prevents discontinuity in a person's time line and avoids paradoxes.

Each TARDIS has built-in controls that prevent the abuse of the first and second laws of time and take evasive action to another time and space should the Blinovitch limitation effect begin. Within these limits, time travellers can come and go as they please in space and time according to Mason's temporal analysis.

Time travel, however, is not instantaneous. Occupants of a time machine will notice the passage of time as normal, and will need to eat, rest and keep themselves occupied on their journey. In TIME LORD, however, the journey is rarely important except when scenes relating to an adventure need to take place. After all, the point at which the TARDIS is going to arrive is often known in advance, and it is from there that the adventure continues.

The TARDIS

Although the Time Lords have created many models of TARDIS, the Doctor's type 40 is probably the only one that characters will encounter. The Doctor obtained his TARDIS only by stealing, or 'borrowing' as he would say, it from Gallifrey many centuries ago: the model is now obsolete and considered a museum piece. TARDISes used by the Master and the Rani are largely similar, although slightly more advanced; a slight incompatibility between circuits means it is unlikely that parts from one type of TARDIS can be safely replaced by those from another model.

In appearance, the TARDIS looks like an English police telephone box from Earth during the 1960s. Close up, however, it is apparent that the wooden lock-up is more than it seems: it hums discernibly, giving away the fact that there is a powerful source of energy beneath its battered blue exterior.

According to the Doctor, the TARDIS is virtually indestructible, although he can be sometimes be panicked into believing otherwise. For added safety, however, the hostile action displacement system (HADS) or the TARDIS force field can be activated.

Inside, the TARDIS is far larger than its external appearance suggests: it transcends the three primary dimensions of the universe. Most of the TARDIS, therefore, exists in another dimension: only part of the time machine materializes when it lands. The TARDIS's doors open into the console room, the location of the time ship's main controls. Beyond the console room, through two ordinary-looking doors, lies the rest of the Doctor's time machine: a confusing maze of corridors and chambers that even the Doctor has been known to get lost in.

TARDIS Features

Chameleon circuit

The Doctor's TARDIS resembles a police box only because of a fault in the chameleon circuit. TARDISes ordinarily look like silver-grey metallic boxes but because this makes them conspicuous, the Time Lords devised a means of disguising them. The chameleon circuit analyses the surroundings of the TARDIS just before the ship materializes and picks an outward form that blends in. A TARDIS materializing on a public beach in Edwardian times might appear as a bathing machine; in a Saxon church it might appear as a crudely carved altar or column. Although the Doctor has made an attempt at repairing the chameleon circuit of his TARDIS, his ship remains in the form appropriate to England in the 1960s; his meddling only resulted in even more bizarrely out of place forms.

Cloisters

Finished in carefully worked and carved grey stone over which climbing plants grow, the cloisters is a tranquil area that resembles its monastic equivalent on Earth. The Doctor sometimes retreats to the cloisters, sitting himself on one of the stone benches or pacing up and down, in order to think clearly about a problem.

Cloister bell

The deep, resounding knell of the cloister bell is a warning that the TARDIS is in great danger, perhaps on the verge of breaking up or entering an area where conditions are so hostile that the ship would be destroyed. Originating from the cloisters, the sound of the bell reverberates through the ship, penetrating every room.

Control console

Most of the TARDIS's functions are controlled from the hexagonal, sloping-topped console that surrounds the time rotor in the main control room. Each incarnation of the Doctor has modified the console in some way, even changing its appearance, to take advantage of new components or to repair damage caused by circuit fires or even blaster damage.

The six trapezoidal panels each house controls for different aspects of the TARDIS's operation. Panel one, nearest the TARDIS doors, houses the basic navigation and steering controls. It is from here that the Doctor sets a course for the TARDIS and initializes dematerialization and materialization.

Moving clockwise, viewed from above, panel two houses the switch that opens and closes the TARDIS's doors and the controls for the scanner. It contains advanced navigational controls that are required in exceptional circumstances only and the TARDIS's defensive controls.

Panel three houses the communications, life support and lighting controls, as well as the room controls. Panel four houses the terminal that gives access to the TARDIS's computer and databanks.

Panel five provides readouts of external and internal environmental conditions, including radiation, humidity and oxygen levels. Panel six indicates the power status of the TARDIS and is used to bring in auxiliary power from generators and batteries. It provides a power outlet for equipment to be used in the control room or a short distance outside the TARDIS.

Access to circuits to carry out repairs is obtained by prising off the control panels or by removing the panels on the pedestal that supports the console.

Control room

The control room is the first room that anyone enters when stepping into the TARDIS. Its main feature is the control console which is set in the centre of the room. Cream-coloured plastics panels cover the walls, with circular mouldings, about 30 centimetres across, concealing electronic circuits and lights. Each Doctor tends to decorate with control room with different objects: the first Doctor favoured ornaments, such as clocks, on pedestals and even a comfortable armchair. Near the TARDIS's doors, a hatstand is practically positioned to keep hats and cloaks for expeditions outside.

Dematerialization circuit

Without a working dematerialization circuit, the TARDIS cannot travel anywhere. The Time Lords disabled this circuit when they exiled the Doctor to Earth; he spent much time tinkering with it in order to escape from the planet.

Dimensional stabilizer

The dimensional stabilizer maintains the spatial relationship of the inside and the outside of the TARDIS. Without it, the inside of the TARDIS would shrink so that its rooms resembled those of a doll's house.

Door lock

Once protected by a number of anti-tampering devices, the lock on the outside of the TARDIS door can be opened only by a specially coded key. The Doctor has removed other forms of security owing to the risk of sealing the TARDIS for ever.

Failsafe switch

Located away from the main control room, the failsafe switch stabilizes the TARDIS in space and time so that it may neither materialize nor dematerialize. Until the switch is reactivated, the TARDIS is suspended in space and time; the switch can be disabled to prevent its unauthorized use.

Food dispenser

Nutritious, concentrated food can be contained from the TARDIS's food dispenser, located in a room near to the control room, by entering the type of food required into the dispenser's computer. The food resembles the concentrated rations used by astronauts from twentieth century Earth during the planet's first space age. The dispenser also issues water in small plastic bags. Although the food is tasty and filling, many companions not surprisingly long for proper Earth meals complete with all the trimmings.

Force field

The TARDIS has a variable strength force field that can be used to keep enemies at bay, provided it is activated. The force field surrounds the TARDIS at a distance of about one metre, preventing both entry and egress. At its lowest level it is equivalent to Strength 10; its maximum depends on the energy available from the TARDIS's generators. The force field generator is located in the pedestal section of the control console and can be detached for use outside the TARDIS.

Hostile action displacement system (HADS)

HADS protects the TARDIS against attack by dematerializing it and rematerializing the ship a safe distance away. The HADS circuit detects the build up and imminent release of energy, and triggers the dematerialization circuit so that the TARDIS makes a short spatial journey. The Doctor, however, tends not to activate this safeguard, mainly because it can make the TARDIS difficult to find and reach.

Rooms

Each companion is assigned his own room in the TARDIS, which he is allowed to personalize. Companions' rooms are typically full of souvenirs from their travels or equipment for their hobbies: Nyssa's room, for example, was partly a bioelectronics lab!

The layout, type and number of rooms in the TARDIS can be controlled from the main control console. Particular emergencies may make it necessary to shed part of the TARDIS's internal structure, and the controls allow rooms to be jettisoned. New chambers usually show the basic structure of the TARDIS, which resembles Victorian ironwork, unless the Doctor remembers to program their features.

Scanner

A large television screen suspended in the wall of the control room provides an image of the location corresponding to the temporal and spatial coordinates of the TARDIS. It is connected to externally mounted detection equipment.

Storerooms

Among the many chambers of the TARDIS are vast storerooms that contain essential supplies and materials necessary to the upkeep of both the TARDIS and its inhabitants. The list of their contents was once kept in the TARDIS's databanks, but the Doctor's poor bookkeeping means that this information is far from up to date -- perhaps as much as five centuries old! -- and may well be inaccurate about the location of equipment.

Swimming pool

The swimming pool is the main feature of a villa-style courtyard that is decorated with white pillars and urns. There is an abundance of plant life in this area: climbing plants creep up the pillars and over stone balconies; the urns contain more formal arrangements. Artificial sunlight makes the courtyard bright and pleasant -- an ideal place to relax.

TARDIS key

Although the key to the TARDIS looks no more complicated than a front-door key, its complex crystalline coding is unique and attuned to the body prints of the Doctor and whichever companions he decides are trustworthy enough to be allowed free access to the TARDIS. The key and lock can be reprogrammed from the main control console. If necessary, the Doctor can issue a spare key to his companions, but he dislikes the risk this entails: his enemies might one day prove clever enough to use a companion and the key to steal his ship.

Time rotor

The time rotor at the centre of the control console rises and falls as the TARDIS travels through time and space. While the ship is stationary, however, the time rotor is motionless.

Workshop

Deep in the TARDIS is a scientific workshop where the Doctor has the facilities to build and repair electronic and mechanical equipment. It has no pretences of advanced technology: ancient scientific apparatus mingles with new and futuristic equipment.

Zero room

The zero room isolates its inhabitants from the forces of the universe, allowing them more easily to attain a peaceful state. The Doctor needed to use the zero room to settle into his fifth incarnation, making use of its therapeutic properties.

A 500-YEAR DIARY

The Doctor occasionally records details of his adventures and the creatures and objects he encounters on them in his 500-year diary. The following extracts are should prove particularly useful to prospective companions.

Antimatter

A safe enough material in its own universe, antimatter explodes violently in contact with the stuff of the normal universe. It can be used only in containment vessels which constantly shift the structure of the containing material so that matter and antimatter never meet.

Black hole

Gateways to the universe of antimatter, black holes exert a strong gravitational pull from which matter and even light cannot escape. Time Lord technology relies on the balancing of the forces of a black hole with the planet of Gallifrey, which is achieved through the Eye of Harmony. The eye is the heart of a black hole that was entered by the Gallifreyan temporal engineer and architect known as Rassilon.

Bessie

A veteran, bright yellow open-topped car driven by the Doctor while on Earth. It is fitted with inertia brakes that allow instant deceleration, a remote control that allows the Doctor to control it from a distance, and an anti-theft force field that restrains potential car thieves.

Camera

A handy method of making visual records of events and people. Often used by the military to identify criminals, as in Invasion of the Dinosaurs, where photographs alerted the Brigadier to the presence of Doctor John Smith and Sarah Jane Smith. Whatever the circumstance, smile if someone takes your picture.

Companion

A guaranteed source of trouble that either gets in the way of experiments, gets captured or gets lost. Companions are useful as early warning systems; they scream loudly should anything dangerous approach.

Computers

'I hate computers and refuse to be bullied by them,' says the Doctor in The Invasion. Computers are infuriatingly obstinate, but liable to blow a few circuits at the slightest logical conundrum. They demonstrate that the evolutionary prospects of an adding machine are limited.

Cricket ball

A cricket ball is an indispensable piece of equipment. It can be thrown at control panels to deactivate automatic security systems, or bounced off a spaceship to use the momentum to rescue a spacewalker whose safety line has snapped or been cut.

Dalekanium

A highly effective explosive developed by the Daleks, and one of the few weapons that is guaranteed to be effective against Dalek armour. A small, hand-sized bomb inflicts 10 Wounds against targets in its primary zone of effect and 5 Wounds to those in its secondary zone of effect.

Earth

Earth is a pleasant green planet with blue oceans which is favoured by the Doctor. It is also known as Terra or Sol 3 and is subject to constant invasions by aliens which know a good thing when they see it. Often unappreciated by its inhabitants, Earth is destined to end up as a ball of chemical goo unless mankind can change its ways. The aliens probably have the right idea.

Environmental helmets

The TARDIS is equipped with a number of environmental helmets that usually form part of a space suit. The helmets can be worn on their own, with or without visors, to provide a suitable and breathable atmosphere. The air supply, however, is limited, and may run out through prolonged use.

E-space

E-space, or Exo-space as it is also called, is the negative part of the universe. It is like the normal universe, only it exists in negative coordinates. Adric, a mutated Alzarian, comes form E-space; the second Romana chose to remain there, ending her travels with the Doctor.

Force field

A force field is a focused barrier of energy that is largely impervious to physical attacks. The Strength of a force field is the difficulty that a character must beat to get through: a typical force field has a Strength of 10. Force fields also act as a type of Armour: if the force field is not breached by an attack, it completely protects anything beyond it.

Fuses

A plentiful supply of electrical fuses is needed for the Doctor's MacGuffins, which frequently overload their circuits.

Timed fuses are essential to use explosives safely: a minimum detonation time of two action turns is recommended for everyone to clear the area of effect.

Galaxy

Often called the universe by creatures, especially science fiction writers, who cannot look or travel beyond their own solar system. As a general rule, there are more galaxies per universe than water molecules in a pint of beer.

Gold

In dust form, gold is a deadly poison to Cybermen; the metal is conveniently worn as jewellery by many companions. Cybermen, however, are probably working on life support systems that do not seize up in the presence of this metal, so the potential of gold is probably limited. It is still useful to appease black marketeers or mercenaries.

Gravitron

Weather on the planet Earth is controlled in the twenty-first and twenty-second centuries by a gravitron based on the Moon. The gravitron exerts huge gravitational forces on the Earth, manipulating the natural weather patterns. The electromagnetic forces it creates can be used to repel attacks against the Moonbase itself by overriding the safety cutouts.

Homing device

Sometimes the Doctor's 'infallible' sense of direction fails him, or his companions need help to find the TARDIS. In such cases a hand-held homing device from the TARDIS's storeroom can be used to indicate the rough direction to the TARDIS. The device is palm-sized.

Janis thorn

Leela uses a janis thorn to paralyse and kill her enemies. Stabbed into the exposed flesh of a victim, the janis thorn releases a Wounds 5 fast-acting poison that attacks once every two action turns. If at any time the poison overcomes a victim's Strength, it immediately paralyses its victim. Subsequent attacks increase the paralysis, resulting eventually in death. The thorn itself inflicts zero Wounds for the purposes of overcoming armour. Leela survived an attack by a janis thorn only because the Doctor was able quickly to synthesize an antidote. The Doctor frowns upon the use of such a dangerous weapon.

Jelly babies

'Hallo, I'm the Doctor. Have a jelly baby,' is the Doctor's usual disarming approach to security guards and would-be rulers of the universe. The Earth confections are a prop used to gain time or favour: only cruel, emotionless or violent monsters such as the Daleks, Cybermen, Autons, Sontarans, Yetis and so on could resist. Jelly babies increase the Doctor's Awareness by 1 if he uses them to charm his way into people's favour.

Laser cutter

A laser cutter is a high-precision instrument for delicate surgery on electronic circuits and components. It can be used in hand to hand combat, for which the Edged Weapons ability is appropriate, and inflicts 4 Wounds. It can also be used for imprecise surgery on electronic components, such as bomb detonators, inflicting 4 Wounds.

Liquorice allsorts

Like jelly babies, this Earth confection has other uses. The Doctor typically lays a path of brightly coloured liquorice allsorts on the ground to distract guards and draw them away from objects they are supposed to be watching. The trick rarely works twice on the same guard. Particularly large and megalomaniac liquorice allsorts tend to have personality defects.

Medical pack

The TARDIS has a dispenser that issues medicine-impregnated bandages that promote the healing of wounds. A dye on the exterior of the bandage changes colour when the wound has healed. Medical packs have the abilities of Knowledge 6, Medicine 2 for the purposes of healing. They are available only if the Doctor has remembered to restock the TARDIS dispenser with the required drugs.

Nestene autojet

The Nestenes' ability to animate plastic and the Master's technological know-how were combined to produce the Nestene autojet, a harmless-looking plastic daffodil. It is programmed to respond to heat and the pattern of a human face, whereupon it shoots a plastic film over the target in an attempt to suffocate its victim. This action can also be initiated by radio signals activated by the Nestenes' human agents or allies. The plastic film is soluble in water, and dissolves minutes after its has done its job by the action of condensed water vapour from its victim's dying breath.

Nitro-nine

Nitro-nine is an effective explosive whose formula is known only to Ace, one of the Doctor's companions. It is unstable, however, and Ace is forbidden to make it: she usually has a plentiful supply. Nitro-nine inflicts 7 Wounds on anyone in the primary zone of effect and 4 Wounds on anyone in the secondary zone of effect. It has a short time fuse of 2 actions turns, so if you have to use it, place it and run!

N-space

N-space is our universe: normal space comprising normal matter. Its counterpart is E-space. Its constituents react violently in contact with anti-matter.

Pocket watch

Each incarnation of the Doctor has carried a pocket watch. Apart from usefully measuring the relative passage of time and acting as an alarm to remind the Doctor of certain events, a pocket watch and chain can be used to hypnotize opponents.

Radiation meter

The TARDIS has a radiation meter built into its control console. It tends to work only after the TARDIS crew has stepped outside. The Doctor occasionally uses a portable meter to measure the extent of different types of radiation away from the TARDIS. This meter is reliable.

Sonic screwdriver

The Doctor's sonic screwdriver is a general purpose MacGuffin that harnesses sonic energy to manipulate and open mechanical and electronic locks. By boosting its power and concentrating the sonic energy into a beam, it can even be used to set off mines. Reversing its polarity turns it into a powerful electromagnet which can be used to draw back heavy bolts. Its ability is equal to the Doctor's total MacGuffin ability, but it is not infallible. It was destroyed during The Visitation at the time of the fifth Doctor.

Space suit

The TARDIS's wardrobe has a reasonable stock of space suits, which are essential for exploration in space and on many moons. An environmental helmet, which provides protection for the head, as well as containing air canisters, can be used separately on planets with thin atmospheres. The length of activity in space suits is limited by the air supply.

Taranium

Taranium is a vital mineral used to power time machines and temporal weapons. It is used mainly by the Daleks to power their time capsules, and a taranium core formed the heart of a Dalek weapon that was intended to destroy time.

TARDIS key

The key to the Doctor's TARDIS is molecularly coded so that only the Doctor or recognized companions can unlock the door. The Doctor has to program the key so that new companions can use the key: the first Doctor is particularly reluctant to do so until he can trust his fellow travellers.

TARDIS toolbox

Useful source of MacGuffins, such as drone clamps, magnetic clamps, neutron rams, laser cutters and probes, that are essential to routine maintenance on the TARDIS. If the Doctor knew how each one worked, he would probably have a fully functioning TARDIS.

Time corridor

A time corridor is a two-way connection between one time and space and another. It is opened and closed from only one end of the corridor, typically on a spaceship or planetary base. Daleks used time corridor technology until their scientists developed timeships.

Time loop

Time loops are temporal traps that keep their victims snared in a short, repetitive cycle of time. The only chance of breaking out occurs if the victims discover at which point they entered the time loop and can then devise a means of changing their actions. Only civilizations that have developed temporal science have a chance of breaking out of a time loop.

Time-space visualizer

The time-space visualizer can look at any event in time and space, provided its operator can program it correctly. It can provide insight into recent events, forewarning the TARDIS crew of imminent danger.

Torch

The TARDIS storeroom carries a number of chemical and electrical torches that are vital to explore some of the dingy caverns in which the craft lands.

UNIT

Earth's United Nations Intelligence Taskforce (UNIT) is a worldwide organization set up in the late twentieth century to investigate and combat extra-terrestrial menaces. Its headquarters is in Geneva, Switzerland, and it has bases near or in the capital cities of the main world powers. Although nominally independent of each country's government, a subsidiary will often be blackmailed by politicians into acting against their leader's will. Each base is dependent on the good will of the host government.

The United Kingdom section of UNIT is headed by Brigadier Lethbridge Stewart, whose regular staff includes Captain Yates and Sergeant Benton. Lethbridge Stewart was first encountered by the second Doctor. The Doctor has since become the temporary scientific adviser to UNIT in the UK, with a pass under the name of Doctor John Smith. He is active in this role throughout the 1970s, 1980s and 1990s.

Whomobile

The third Doctor built a special car during his sojourn on Earth. The Whomobile is a compact, silver car with curved, sweptback wings. It can fly: in the air it is treated as a light aeroplane with Move 7; on the ground it is treated as an air car with Move 6.

Zyton 7

The prison planet Varos is the main source of Zyton 7, a key element in the power sources of many spaceships. The Time Lords use it to power type 40 TARDISes like the Doctor's owing to its long life. The TARDIS's Zyton 7 has been exhausted only once in many centuries of time travel.