Jeff, Britta, Annie, and Shirley have gathered to say goodbye to Troy before he leaves for his trip around the world. As a going away present they give him a universal translation device. Britta tries to get the group to acknowledge that they are sad that Troy is leaving but they try to ignore her.
The Dean comes on the intercom with an announcement. He and announces that Abed wants to send off his friend Troy with a special gift: a school wide game of "Hot Lava", a game where players have to avoid touching the floor or they will be "killed" by the "lava." The study group enthusiastically agrees to join in, except for Britta who sees it as a way for Abed to avoid engaging with his real feelings about Troy's departure. Abed announces that, in order to motivate everyone to play he has offered a prize to the last person alive: his near mint copy of Space Clone issue #1, valued at $50,000 by the comics authority. Across campus, people scramble on top of chairs, tables, and lockers.
Some time after dark. Britta climbs across objects which have been placed on the floor, creating makeshift walkways. She find Professor Ian Duncan and explains that she is staying in the game so that she can talk to Abed and get him to deal with his feelings. Duncan explains that he's "not afraid to push a girl into fake lava" and goes after Britta but she is saved by Annie and Jeff who show up and knock Duncan onto the floor.
Britta agrees to go with Annie and Jeff so they can find Abed. The three of them use a couple of plastic chairs to "centipede" down the hallways, placing one chair in front of the other and then repeating the process. As Britta explains her motivations to Jeff, Annie spots a large stack of chairs at the end of the hallway which will potentially give them the mobility they need to win the game.
When they centipede closer to the chairs they start hearing noises from the lockers around them. Suddenly, the Locker Boys spring out, using objects like crutches and mops to menace Annie, Britta, and Jeff. The Locker Boys are lead by Chang who demands that the trio give them their chairs, their food, and the names of their same sex celebrity crushes. Before the Locker Boys can attack, Troy and Abed "inchworm" into the hallway, using two chairs each to crawl across the floor. They assume an "intimidation stance" and the Locker Boys attack.
Just then Buzz Hickey arrives, driving a motorized contraption he has made. The members of the study group flee as Hickey barrels down the hallway, knocking over the Locker Boys. As he "dies" Chang admits that his same sex crush is Nathan Filion.
Hickey then comes after the study group. As they flee, Abed tricks Britta into leaving the centipede formation and he and Troy abandon her. Troy promises to remember "how you always slowed us down." As Britta tries to flee on top of a garbage can, Hickey stops his cart, astonished that they abandoned her. He says that he's only in the game to help pay for his son's gay wedding. "The flower's alone, you have no idea." He explains. "I know" Britta says "I lived in New York." He tells her he'll give her a ride.
Abed, Troy, Annie, and Jeff arrive at "Shirley Island" a refuge which Shirley has created in the cafeteria. When they inform her that Britta is dead she notes her passing on a board divided between "Christians" and "Secular" students. Abed says that legend has it that Shirley Island is the location of "The Orb" and pressures her to reveal its location. Troy warns Abed that he doesn't want people to hate him on his last day. This seems to get to Abed but before he can go further they hear Hickey calling them on a bullhorn.
Hickey has a group of a half dozen "chair walkers", students who have duct taped chairs to their feet for added mobility. They threaten to attack Shirley Island if the inhabitants don't surrender. Britta then comes out on a rolling chair, using two plungers for propulsion. She tells them that she will force them to confront their feelings. Abed and Troy are forced to admit to their friends that they left Britta for dead. Shirley refuses to surrender, stating that she is missing her son's birthday for this. Britta then orders the chair walkers to attack.
As the chair walkers begin to tear apart Shirley Island, Shirley orders Leonard to "butter them up". He then pumps popcorn butter onto the floor, causing many of the chair walkers to slip and fall. Leonard taunts them with "Cirque du So Long you high stepping acro-bastards!". Annie and Jeff board rolling chairs and use a cable to snare and trip the remaining chair walkers, but Annie falls off the chair and 'dies' in the process.
Jeff steals one of Britta's plungers and challenges her to a duel, while trying to engage her in witty trash talk. However, Britta ignores his attempts to bait her into a knock knock joke and bests him at the duel, knocking him to the floor and taunting him by saying "Who's there, bitch!? Floor! Floor!"
While Jeff and Britta duel, Abed asks Shirley for The Orb, saying that with it he can save Shirley Island. She explains that the Orb isn't on Shirley Island, the Orb IS Shirley Island. She then reveals the Orb, a giant inflatable ball which people can ride in. Abed and Troy get inside and use it to attack Hickey, singing "Troy and Abed in a bubble!". Hickey roars past them on his scooter and uses a knife to cut the Orb, slowly releasing its air.
Troy and Abed flee down the hall in the Orb, with Britta and Hickey giving chase. Britta then jumps on top of the Orb, telling the two "I'm going to force you to face your true feelings even if it kills us!" Britta is knocked off the Orb and onto Hickey's scooter when the Orb rolls trough a doorway and into the basement.
Abed and Troy escape the Orb and begin climbing across shelves. Troy says that maybe the game has gone on long enough but Abed doesn't want it to end. He explains that he's seeing real lava because Troy is leaving and wanted to create a game so that everyone else would see the same thing as him. Hickey and Britta arrive in the basement, using a book case to "surf" down the stairs. Troy tells Britta that Abed is really seeing lava. Hickey pushes the shelves, knocking them over and forcing Abed to hang from a ceiling pipe. Angry at Hickey, Britta pushes him onto the floor.
Abed explains to Troy that he doesn't think the lava is there because Troy is leaving. Rather, the lava is there because he can't let go. He lets go of the pipe and falls the floor where he "dies" and remains unmoving. Britta goes over to Troy and they try to get Abed to get up. But they realize that Abed's commitment to the game won't allow him to simply come back to life. Instead, Britta, looking at Abed's copy of "Space Clone" gets the idea to "clone" Abed. They make a cloning machine out of boxes and use it to "clone" Abed. Abed gets up and explains that Britta's cloning worked, but has cured him of his excessive emotionality. He says that he's ready to let Troy leave but Troy wonders if he himself is ready to go. Abed explains that Troy can send his clone instead and Troy agrees, falling backward onto the floor.
Later, everyone gathers outside Greendale to say goodbye to Troy. Troy tells Annie that he wishes he had paid attention to her in High School and that he missed out on four years of her friendship. Jeff tells Troy that he's never even been outside of Colorado and envies Troy's adventure. As Troy prepares to board Pierce's boat, the Childish Tycoon, which is parked outside, he says that Pierce arranged for someone to travel with him to verify that he actually accomplishes the task. That someone turns out to be Levar Burton who appears on the deck of the ship. A surprised Troy boards the boat and he and Levar Burton ride off.