The Gist of It: The episode opens showing scenes from a couple previous X-Men Evolution episodes, the Self-Possessed scene in which Rogue startes touching people at the concert and the climax of Mindbender where Mesmero reveals his plot for getting the three rings and merging them into a key.

A shadowed figure hops a fence into a high security complex. At the front glass door of the complex it's revealed to be Gambit, he uses Kinetic energy to melt the glass. Gambit then uses some spray to reveal laser sensors on the floor, assembles his lance and shoots two arrow projectiles out of each side, they grab onto the wall. He glides across safely about halfway to the other side, cuts a hole in the floor using his powers and claims his prize (which appears to be half of a spider statue). During this Angel wakes up. As Gambit grabs the spider half Angel comes out of his room confronting him. Gambit attempts to blow Angel up with a charged card but fails and escapes by hopping the fence again, going to deliver the half of the spider to Mesmero. Angel catches up with Gambit at this time and flys in for an areal assault but is interrupted midair by a psychic attack from Mesmero. Gambit hands the Spider half to Mesmero.

After the credits it returns to the same scene. The metalic fence starts bending and reshaping, the bars are removed from it and surround Mesmero. Magneto appears, Mesmero attempts to use psychic powers on him but fails. Mesmero starts to control Gambit into attacking Magneto, but Magneto tightens the bars around Mesmero and orders him to release Gambit. Mesmero cooperates and does so, Gambit is confused on where he is. Magneto is curious on why Mesmero wanted the spider half and decides to investigate, using the bars to break the peice of concrete in which Mesmero was standing to carry him off in flight. Angel is left behind and says "Magneto".

Back at the institute a baseball game is going on. Jean is pitching (I had trouble recognizing her in the outfit in fact), Bobby is at bat, Scott is catching and Beast is playing umpire. Bobby teases Jean a little bit sort of telling her to bring it, she replies "yeah I'll bring it alright" and the ball starts hovering from telekinesis. Bobby complains to Beast about this but Beast ignores it, just saying plaaaaaay baaaaall. Scott teases Bobby and tells Jean he's "no batter", Jean throws the ball and enhances it with telekinesis to fly faster. Bobby ices the bat making it much larger and hits the ball. Beast says "here we go". Bobby yells "mutant ball" and the fun begins. Jean is being pitched to, as the ball approaches and she Telekinetically stops it midair hitting it. Cannonball dives into second using powers which Kurt narrowly avoids by teleporting out of the way. Magma is now pitching and she hurls a fireball towards Beserker. Scott yells whoooa and dives out of the way, Beserker swings but the ball goes straight through the bat, then through the fence. At bat Sunspot charges and hits a huge drive, Scott immediately gets up and optic blasts the path to first base making Sunspot trip on the way there. Kurt teleports into midair to catch the ball, then teleports in front of home plate to block Kitty's path. She phases into the ground and reappears to touch home plate from below, Scott calls her safe. At this point the game is interrupted from the sun being blocked out, everyone looks up to see Angel flying above the game, he lands on first base. Scott approaches him asking what's wrong, Angel says he needs to see Professor Xavier immediately.

At Magneto's hideout, Mastermind is probing Mesmero's mind. Magneto enters the room and Mastermind tells Magneto his plan, to get the other spider half to form a key. Mastermind also tells Magneto the other half of the spider is in London. Magneto wants to know what the key goes to but Mastermind can't find out yet, Mesmero is blocking him. Magneto spins Mesmero around in his chair shaking him up and Mastermind probes his mind once again, to reveal his motive. Mastermind gets a few flashes of Mesmero opening the first door, then tells Magneto what Mesmero is plotting to do - free Apocalypse.

In the Institute a picture of Mesmero appears on the screen of a super computer. Professor X asks if Angel is sure that's the guy he saw, Scott tells him it's not a face you'd easily forget. Kitty and Amara are looking into the room and Bobby approaches asking if they're staring at the new guy, they just walk off. Bobby sneaks into the room to get a better look. Xavier explains to Warren that Mesmero manipulates others to steal for him and shows what happened in Mindbender, the assembling of the first key. Bobby interrupts this meeting with a "let's go" attitude but Beast tells him he's not welcome, they don't need a member who doesn't follow rules i.e. icing a baseball bat in a game, was Jean's example. Bobby begs but they just walk away.

At Magneto's headquarters is appears Mesmero escaped with the artifact, it disappeared and he did too. Magneto is pissed off about this news as Mastermind informs him about it.

Rogue is visited in her hospital room by Kurt bringing her food, Kitty's enchiladas with her special sauce. Rogue declines the food and asks where Logan is, Kurt tells her that he's looking for their mother. Kurt informs her that Xavier is in London, so Kitty and him are taking care of her. He tries to feed her but she tells him to go away, Kurt says "is that really a way to treat your little brother?". Her eyes widen in anger saying Mystique gave birth to him but she just adopted her. Kurt replies that either way they're in this together and tells her he's there for her, then teleports off to get Kitty to make her an anchovie jalapeno pizza.

The X-Copter lands on top of a museum and Beast comments how quiet it is saying maybe they got there first. Xavier says lets hope so, and tells Scott to inform the "stowaway" they've arrived. Scott questions this and opens the compartment in the back to reveal Bobby stuffing his face with chips. Scott asks if he has anything to say for himself, Bobby makes a comment about that being the last time he flys no thrills. Magneto arrives at the front of the complex and busts through the front door with magnetism. A guard playing solitare inside see's the alarm going off and makes a call to tell someone to fix the bugged alarm. A floating inflamed card lands on the table and Gambit says a few words, then the card explodes knocking the guard back against a closet. Gambit shoves him inside the closet and locks him in with a chair. Gambit continues the game of Solitair. Another guard is patrolling the hall next to some Knight armor figures. Colossus is standing there in metal, as the guard passes him he notices something wrong, then turns back to see Colossus. Colossus grabs him. A flaming horse is chasing another guard down a different hallway and Pyro is following laughing. The guard runs into the storage closet and Pyro says "don't fret mate, we'll be out of here in 5", then melts the handle.

Bobby is approaching the door with the rest of the team, which includes Scott, Beast, Jean, Angel and Bobby. Bobby makes a comment like "oh yeah, definately the cool team". Scott notices that Magneto is already inside, Beast orders Bobby to stay with him. Bobby replies that he has Beast's back, Beast replies he doesn't have a clue.

Magneto gets out of an elevator and notices a shadowed figure walking down the hall in front of him. He magnetises the elevator to break off and follow.

Sabretooth is walking next to a window and notices a long haired figure outside, before he's telekinetically lifted and a curtain is wrapped around him holding his place. Bobby ices beast from the roof to the floor, Sabretooth breaks out. Scott shoots him with an optic blast flying back into metallic Colossus. The rest of the Acoloytes are grouped now and Gambit says "I think they want to play".

Magneto sees Mesmero again and makes the elevator pursue him.

Angel is dodging kinetically charged cards from Gambit and makes them fly back at him with his wings. Gambit jumps out of the way and the pillar they hit starts to fall, but is grabbed by Colossus. As it flys towards Scott, Scott uses an optic blast to destroy it. Beast is climbing around in the rafters as Pyro tries to shoot flames at him. Sabretooth picks an exhibit up and hurls it at Beast who's currently staring straight into a wall. Before it hits him Bobby creates an ice shield protecting Beast, then says "Iceman has your back". Jean tells Beast to tuck and roll, then lifts him with Telekinesis and he jumps on top of Sabretooth. Angel is harassing Gambit by flying at him. Pyro makes a fire angel duplicate and starts chasing him, but Bobby comes down to the rescue by icing Pyro's hands.

Mesmero is running from Magneto and the killer elevator to the other half of the spider. The cables grab him by the feet and throw him in, Magneto compacts it with magnetism. As Magneto grabs the other half of the spider with magnetism, the two halves react to each other and combine together, then start glowing. An explosion goes off and the stone spider turns into a living walking 15 foot tall spider. Mesmero laughs and walks off. The spider is trying to get away but Magneto is holding him back with magnetism, but the spider breaks away soon. Magneto's acolytes are at the front of the complex again where they broke in and Magneto orders them to destroy the spider. Charles asks Magneto to stop, but Magneto says no doors will be unlocked and flys off. The X-Men regroup and Xavier tells them to capture the spider so they can investigate. Colossus is running after the spider breaking through several walls, then tries to tackle it. He fails and is grabbed, then I think he's electricuted. Sabretooth is on a rooftop with a wooden log, raising the question where he got it from. Anywho, he jumps down onto the spider and swipes at it a few times but then is tossed away on top of a van. Pyro shoots flames at it and yells "yeaaaaaaah barbeque spider". The spider goes underground to avoid it though, and Pyro has to jump away. The spider now jumps into water, Gambit watches from an elevated area and runs off.

Xavier approaches Mesmero and tells him he wants answers, then begins to probe Mesmero's mind. This reveals Mesmero's plan and Magneto says "Apocalypse". Mesmero disappeared.

Jean lifts the spider out of the water with telekinesis, but the spider counters and knocks her to the ground, before she lands she's saved by Scott. Scott tries to slow it down with optic blasts and Jean warns him about being careful not to destroy it. The spider gets away, Beast orders Bobby to ice them across the river. The spider is causing terror in the streets as people are running and fleeing. It also appears the spider has grown quite a bit. Gambit spots this going on from his stolen bus, then flips it over and jumps out on top. Right before impact with the spider Gambit jumps off the top of it. The spider is trapped under it, and Gambit charges the bus to explode. The spider is temporarily down as the X-Men get there. Magneto starts to use Magnetism to destroy the spider and Xavier begs him to stop. Magneto continues anyway and the Spider is destroyed into a melted statue of what it was before. Xavier comes up to Magneto and tells him he's done the very thing Mesmero wanted him to do, and reveals the spider was actually something that hindered Apocalypse from being freed. Magneto is shocked about this. Angel tells Beast Mesmero was heading directly southeast. Xavier tells them he doesn't know where he was going, but they need to stop him from getting the last key. The episode ends with a short clip of the second door in Apocalypse's tomb opening.

-End of Episode