A woman is jogging through the woods, unaware that something is stalking her. It finally leaps out and attacks her, dragging her into the woods. Two men hear her scream and go to investigate, and find her dead.
George shows Jim photos of the dead woman, noting it has five claws instead of four and didn't leave any tracks. Jim asks George to check with the coroner, suspecting that a super is responsible. At home, he suggests to Stephanie that she try to use her access to the project to find out who else that Dr. King has experimented with.
At school, Daphne mentions to Chris that Sara Bareilles is in town filming a video. He figures that she wants to ditch and suggests she use her mind control to do so, but Daphne insists that she doesn't want to overuse that power on others. She also says that she has a history paper to write. Chris gets her to reluctantly agree to ditch with him if she finishes the history paper.
In decathlon practice, J.J. receives different equations than his teammates. When he questions Litchfield about the discrepancy and how the equations are tougher than anything they'd face in competition, Litchfield just tells him to do the work.
Stephanie goes to see King and asks to see the database of patients so she can see what side effects occurred when they received treatment. She brings up the jogger's death, but King insists that they haven't had anyone with that ability.
Lucas Winnick is on the street, using his newly-gained claws to scratch cars. Mrs. X pulls up in his limo and he gets in, and she asks if he's an idiot. She warns him that he screwed up by leaving the body, and that an autopsy may compromise his identity. Winnick says that he had no choice to leave it because the hikers were coming, and Mrs. X tells him to retrieve the body.
At the morgue, the coroner calls George and says there's something he has to see. When George and Jim arrive, they find the coroner dead, clawed to pieces, and the jogger's corpse gone. Back at the lair, Jim figures that someone took the body and killed the coroner to cover their tracks. Stephanie goes over the coroner report and confirms that the corpse contained chemicals similar to those in the Powells' blood. A report of an animal attack comes in on the radio and Stephanie and Jim go to investigate.
Chris approaches JJ and asks him to write Daphne's history report so she can cut school and go to the Sara Bareilles video. When JJ balks, Chris threatens to reveal his superpowers to the public. JJ goes to confront Daphne, realizing that she told Chris the family secret. Daphne says that she doesn't want to lose someone who knows what she can do and cares about her. JJ agrees, but asks her to read Litchfield's mind and find out why the decathlon is so important to him.
Jim goes to the house where the animal attack occurred, and the officer reveals that the body disappeared. The victim was a drug addict and the walls are covered in blood and claw marks. Outside, Jim tells Stephanie what he saw and she invisibly superspeeds inside to take the syringe and confirm that the addict was taking trilsettum.
Daphne and Chris try to sneak out, but Vice Principal Nance spots them and asks what they're up to. Daphne panics, but Chris tells her she can do whatever she needs to. When he orders them to his office, she uses her ability to convince him to excuse them from class and give them some money for gas.
At the lair, Jim, Stephanie, and George go over the information and try to figure why someone is targeting villainous supers. George figures that they're better off dead, and doesn't see the point of putting their lives at risk to stop the killer. Stephanie insists that none of the transformed patients deserve to die, and George gives in. They try to figure out where the animal killer is heading next.
Katie arrives home and finds Winnick waiting for her. He asks where the Watcher is, and Katie says that he isn't staying with her anymore because they broke up. Winnick accepts her claim and starts to leave, but then smells something from Katie. He realizes that it's her and reveals his fangs and claws. As she insists that she's not a super, someone telekinetically throws Winnick into a car.
Later, Katie calls over Stephanie and Jim and insists that the Watcher must be nearby. She panics and telekinetically hurtles something, and they realize that Katie's attacker knew she had superpowers. Jim and Stephanie realize that the killer is going after supers and will target JJ and Daphne. As they leave, Winnick watches them and calls Mrs. X to say that the Powells have superpowers and they're not on her list of supers. She tells him to kill them all.
Litchfield calls King to tell him that JJ won't do the work. King isn't impressed, and tells him to deal with the situation. The bell rings and Litchfield confronts JJ, and tells him that he needs to finish the equations. JJ tries to leave, and Stephanie arrives to take JJ out of school on a "family emergency." Outside, Stephanie asks where Daphne is, and JJ claims that he doesn't know. However, he does admit that he knows Daphne is with Chris and they ditched.
Chris and Daphne arrive at the video shoot, and he convinces Daphne to use her powers to get past the security guard.
Katie works with Jim to make a sketch of her attacker. George is less than thrilled that the other sidekick got superpowers. Once they have a sketch, Jim brings up the police records and Katie spots Winnick. The records say that he's on death row. Stephanie and JJ arrive, and Stephanie confirms that Winnick was the patient that she injected. Jim heads out for Winnick's last known address, while Stephanie goes to the house to find Daphne.
At the Powell home, Winnick goes through Daphne's room and spots the advertisement for the Sara Bareilles videos shoot. He gets Daphne's scent from her clothes and then hears Stephanie as she comes home. Winnick confronts her and assures her that he has Daphne's scent. He assures Stephanie that he's happy she transformed him, and she asks him to spare his family. She superspeeds ahead of him and tells him not to waste his second chance. Winnick wonders if she would do that for him and he retracts his claws as Stephanie says that she understands what he's going through. As she approaches him, he guts her and says her concern means nothing to him, and then leaves to kill Daphne.
At the lair, Katie tries to consciously use her powers without success. Jim returns and reports his lack of success. When he realizes that Stephanie hasn't returned, he goes home and finds the injured Stephanie. She assures him that she's a fast healer and tells him not to call 911. Stephanie blames herself for creating Winnick and cries out for Daphne.
At the video shoot, Daphne thanks Chris for bringing him, unaware that Winnick is in the crowd trying to pick up her scent.
Jim takes Stephanie to the lair, and she tells him to find Daphne. He asks JJ to hack Daphne's emails and he reluctantly does so, finding a text message from Chris.
At the shoot, Daphne gets a text message from Jim and finds somewhere away from the music to call him back. Winnick approaches her and says that the school sent him to tell her the bad news that her mother has been attacked and taken to the hospital. He says that there's no time for her to tell Chris, and she reluctantly goes along with him. As they go, Winnick explains that Stephanie was attacked at her home, and transforms into his animal form. Jim leaps in and knocks Winnick away, and tells Daphne to get away. Winnick comes after him but is unable to penetrate his skin. The two of them leap into the air and Jim tackles Winnick and knocks him back. The two of them smash down onto the ground and Jim finally gets the upper hand. As he beats Winnick, Daphne arrives to stop him before he kills Winnick
Back at the lair, Stephanie's condition worsens and Katie explains that she's contracted an infection. JJ analyzes her room and concerns that she has staph bacteria. He and Katie come up with a possible cure, but Jim says there's only one doctor they can take her to.
Jim brings Stephanie to King and explains that Winnick attacked him, and tells King that it's time for the games to end so they can save Stephanie's life. King agrees to help and starts treating her, but warns that the infection is too widespread. Jim suggests that he administer trilsettum, no matter what the risk. King agrees and starts to give Stephanie an injection, but Jim insists on doing it for his wife. When nothing happens, Jim wants to give Stephanie another shot but King advises him to wait. Stephanie recovers consciousness briefly and Jim tells her to rest.
At school, Daphne comes to drop off the equations that JJ completed. When Litchfield reads them, she reads his mind and hears him thinking that "he" would kill him if he didn't get the equations. Daphne quickly leaves and calls to leave a message for JJ that they need to talk. Chris catches up to her and asks about Stephanie, and then says he had a lot of fun with her. Daphne suggests that they take a break from using her powers, but Chris says he has a wish list of things they can do using her powers.
King receives the email from Litchfield with the equations and smiles in triumphant. Mrs. X, the CEO of GlobalTech, comes in and demands to know why the supers are running free. He apologizes, but Mrs. X says that it's her fault for letting him working without oversight. From now on she plans to oversee everything he does, and asks if there are any more surprises. King tells her that he's close to solving the equation for power permanence, and shows her JJ's work.
Daphne comes to the lab to get Stephanie's files. Katie is there and explains that she has powers because the Watcher impregnated her.
Jim arrives home and Stephanie greets him. She's ready to go for a run, and insists that she's fine. Jim worries that there could be side effects, but Stephanie insists on going. She goes outside and runs, but finds herself starting to dissolve into light.