Biology breaks the students up into teams and has them work on dissecting a rat. Gabe tries to hypersuade Ian to do the project, but Ian is well aware of his friend’s abilities. Their third team member, Fenton Capwell, is running for Class President against the incumbent, Emily Wright. They bargain with Fenton to do the project in return for their votes. Fenton agrees, noting that his father is a surgeon and dissection doesn’t bother him. However, as he starts to cut, his hand trembles and he then collapses. Ian has Biology call Nurse. She has the Monitors take Fenton to the infirmary and assures him that he’ll be okay. As he’s taken out, Ian and Gabe promise to visit him. Ian notices Headmaster in the hallway outside, looking worried. When Headmaster realizes that he’s been noticed, he quickly leaves.
That night in their room, Ian and Gabe talk about Fenton’s collapse, and Gabe considers running for office in Fenton’s place. Ian notes that they’re planning to escape, but Gabe figures that if he can win the election, he can use his position to find out some of the secrets of Tower Prep. Ian doesn’t buy it, and Gabe admits that he’s jealous that Ian is the one who comes up with the plans. Ian warns him that Emily and her campaign manager, Ross Anderson, won’t be easy to defeat. Gabe is confident that he can use his skill to win. Ian drops the matter and starts working on his homework, and notices that his hand is trembling, just like Fenton’s did.
The next day, Gabe meets with CJ and Suki, who warn him that Emily is popular with the student body. They suggest that he do well at the election presentation, but Gabe is obsessed with learning one thing. Ross comes by and asks Gabe if he’s planning to run. When CJ intervenes, Ross says that Gabe needs to speak for himself, and tells him that he’ll be crushed. Ross warns that it’s nothing personal, just business, and she always takes care of business. With Fenton out of the way, Ross figures that they have nothing to worry about. Confident in her candidate’s chances of winning, she tries to give Gabe one of Fenton’s anti-Emily election badges. CJ takes it instead and pins it to her jacket.
In the skills lab, Ian is playing rushball against Ray Snider’s team, and using his preflexes to win. Ray uses his teammate as a shield to protect himself, and Ian goes for one of the balls to win the game. However, he’s seized with sudden weakness and Ray tags him in the head. Coach breaks it up and Ian insists that he’s okay. Coach isn’t convinced, but Ian claims that it’s stress. As Coach leaves, Ian notices his hand trembling again.
Ian is sparring with the other students in the skills lab in a game of rushball, and using his preflexes to stay one step ahead of Ray. Ian takes out Ray's partner and goes for one of the throwing balls, but freezes up. Ray hits him in the head, and Coach warns him against head shots. Ian insists he's okay, and Coach helps him up. Coach wonders how let himself get hit, and Ian claims that it's stress from midterms. Once Coach leaves, Ian notices that his hand is shaking again.
Ian, Suki, and CJ are at the observatory working on their homework when Gabe arrives. He tells them that he’s found the electron rule booklet, and that the rules require that all election badges have to be distributed evenly. Ross and Emily are holding out. CJ finishes Gabe’s new election poster, but Suki thinks that it looks familiar. While they talk, Ian gets a headache and tells them to focus on escaping. Gabe realizes that he’s upset and asks him to talk about it, while CJ uses her ability to realize that something is going on with Ian. Ian notes that nobody has seen Fenton since he was taken to the infirmary. As he talks, CJ tries to scan him for more information, but comes up blank. When Ian leaves, CJ admits to Suki and Gabe that her ability seems to be on the blink.
Ian breaks into the empty infirmary and starts to check out a book on Nurse’s desk. She arrives and explains that Fenton is under medical supervision. She comments that Ian looks tired, and insists on checking his hand to see if it’s trembling. Ian claims that it’s fatigue, but she says she needs to take a blood sample to determine if he has caught any pathogens that his body hasn’t built up a resistance against.
As Gabe and the others go to put up Gabe’s poster in a heavily trafficked corridor, they realize that CJ’s posters have the same style as Emily’s, and that she inadvertently copied them. Ray and his friends go by and try to rip Gabe’s one poster down. Ian arrives and tries to stop him, and Ray rips off his anti-Emily badge that he’s wearing. Ian tells him to pick it up, and Ray attacks him. Ian tries to stay out of his way, but his preflexes fail him and Ray lands a punch, knocking Ian back with his super-strength. Suki tries to distract ray by impersonating Headmaster’s voice, but Ray tries to punch Ian. Ian dodges at the last second and Ray slams his hand into the floor, injuring it despite his invulnerability. The students call for Nurse while Suki picks up Ian’s badge.
The fringers meet back at the observatory, and CJ admits that she’s suffering from the same symptoms as Fenton, Ian and now Ray. They figure that Nurse and Headmaster know what’s going on, and Ian prepares to use the hidden passageways to get to Headmaster’s office, alone. The others want to go, but Ian warns that he could risk exposing them in the close quarters. He tells Gabe to focus on his presentation and win the election. As Ian leaves, Suki’s hand starts to tremble.
Ian gets to the vent above Headmaster’s office and listens as he discusses the situation with Nurse. Headmaster wonders if it’s like the situation in1971, and Nurse assures him that it’s difference, and that they were careful at the time despite the Headmaster of that period, who tried to destroy the purpose of Tower Prep. They figure that whoever is responsible for the outbreak now is being reckless. Nurse says that she’s going to check her lab tests for the presence of Chemica Desin.
Next, Ian returns to the infirmary and searches Nurse’s laptop computer. He finds a file labeled “Chemica Desin” and discovers that it’s an inhibitor. When someone comes into the infirmary, Ian hides beneath the desk, but the intruder finds him. It’s Emily Wright, who explains that she respected Fenton and is Ray’s friend. She figures that something targeted both of them, and Ian explains what he heard Nurse and Headmaster say. Emily tells Ian that she saw the Chemica Desin file on Nurse’s computer by accident the other day when she came to see Ross, who is in work-study at the infirmary. She decided to sneak back in to find out more. Emily says there are rumors that outsiders have been seen in the school, and they wonder if they might be from the 1971 project and have returned to take control of Tower prep. Nurse starts to open the door, and Ian and Emily quickly hide. As she checks her computer, Ian notices that his blood sample and the blood test result are on the desk nearby. He manages to grab them and then leaves with Emily. Nurse hears a noise and realizes that someone has been in the room.
The next day, Gabe confronts Ross with the regulation book and tells her that she has to split the badges evenly with him. She agrees, and Gabe starts putting his own labels on them with his campaign slogan. When Ian arrives, Gabe tries to give him his anti-Emily badge, the one that Ray ripped off, and explains that he plans to end his speech at the presentation by throwing his badges into the audience. Ian reluctantly admits that he likes Emily and doesn’t want to wear the anti-Emily button. Gabe gets him to wear a pro-Gabe badge, and Ian reluctantly attaches the anti-Emily one to his backpack beneath the flap.
Ian checks on Suki and CJ, who are getting worse. Ian explains that his blood test results confirm that he has Chemica Desin, and that they have no choice but to go to Nurse to see if she has a cure. CJ figures that the authorities must have created a vaccine in 1971, and they realize they need a microscope to analyze Ian’s blood sample. Ian gets Emily and they go to see Emerson Poercet, who has microscopic vision. He confirms there’s a film on Ian’s red blood cells, and they realize that Chemica Desin blocks enzyme inhibitors, removing their skills. Ian tries to contact Gabe, but he’s busy rehearsing his speech with CJ and Suki and has turned off his pager. Emily figures that the bonding film will soon become permanent, and they have to find a vaccine before it’s too late. They figure that Nurse has it in the infirmary. However, as they go, Emerson sees microscopic traces of Chemica Desin on the anti-Emily badge on Ian’s backpack. He also sees six sets of fingerprints. Five of them belong to the five infected people who touched the badge, while the sixth set belongs to… Gabe. Ian tries to get out but collapses, and he warns Emily that Gabe plans to throw his own badges, now contaminated by his touch, out into the audience, spreading the disease. He tries to call Gabe again, and Emily pricks herself on the anti-Emily badge when she tries to help Ian.
Gabe wants to stay with Suki and CJ, but they insist that he goes and give the presentation. He leaves, his pager still on the table.
Ian goes to the observatory to find Gabe, and Emily goes to the auditorium to find him. CJ and Suki tell Ian what happened, and realizes that he has to get them to Nurse before it’s too late. Despite his own increasing weakness, he gets them out.
Emily is in the hallway when she starts to feel the effects of Chemica Desin. She collapses and two students help her to the infirmary. Gabe walks by, unaware. He enters the auditorium and nods to Headmaster, who is watching over the assembly. Gabe looks for his competitor, but only sees Ross, looking nervously around for her client.
Ian gets Suki and CJ to the infirmary and asks Nurse to treat them, and she realizes that Ian is sick as well.
After waiting 15 minutes, Headmaster calls the assembly to order and asks Ross where Emily is to be found. Ross has no explanation, and Headmaster has Gabe take the podium to give his presentation. Gabe starts to speak and some of the audience jeers him. His powers don’t work, but he rallies and speaks movingly of whether they are students or citizens.
Nurse explains to Ian and the others that the 1971 Headmaster came to the conclusion that he could remove the students’ special skills, making Tower Prep unnecessary. His scientists created Chemica Desin to do so, but the next Headmaster put an end to it by having his own scientists create a reversal agent. Nurse admits that someone has found an old Chemica Desin sample, and modified it so that the original inhibitor no longer stops it. One sample of the disease was kept in the infirmary for experimentation. As the students bring Emily in, Ian remembers that she said that Ross was a work-study worker in the infirmary, and had access to the sample.
Gabe finishes his speech and prepares to throw out his buttons. Ian arrives just in time to stop him, and then explains that Ross’ plan was to eliminate the competition, but things got out of control. He collapses, and Ross tries to escape. However, Headmaster easily stops her.
Later, everyone has recovered. In science class, Biology notes that Emily and Ross worked together to create a new cure to the inhibitor, and Ross was then banished to West Campus. A triumphant Gabe claims it as the first success of his administration, and tries to declare a homework-free day. Biology gives him a 10-page assignment on the new inhibitor.
Headmaster and Nurse talk to Ross and get her to admit that she modified the inhibitor using her biology class lessons and Tower Prep equipment. She prepares for banishment to West Campus, but Head master says that she’s impressed them, and offers to forgive her in return for her sharing the secret of the inhibitor. Ross agrees, smiling.