At the Lawrence house, Minx is on her bed, writing in what looks to be her diary. She asks Drill what is next and writes what he tells her in her diary. At the Bennigan house, Henry is starting his day when he sees Minx in the next room. Minx and Henry meet for the first time and she knows he can hear. She tells him Drill sent her over to play and she reveals that Drill can help him find his father as long as he helps Drill by playing a game.
Claire and Wes arrive at the power plant and are met by Jessup. The three meet with two officials and Claire and Wes share their information about Sean. Jessup receives a call about a car wreck not far from them that matches the car stolen by John Doe, who they now know is Sean Bennigan. Elsewhere, Minx gets Henry to play the game with her, sending Henry on a mysterious “scavenger hunt.” At the plant, Claire, Wes, Jessup and the crew try to figure out why Sean is headed there. Suddenly, there is an evacuation alert. While everyone is headed out, Sean and his hostage, Dr. Benavidez, head in.
At the Bennigan house, Henry’s grandmother calls out for him only to be startled by Minx. Minx distracts her by telling her she has small cut and is in need of a Band-Aid. When the grandmother questions Henry’s whereabouts, Minx tells her he’s riding his bike. Meanwhile, Henry is playing the game, following Minx and Drill’s scavenger hunt. At the plant, the security cameras malfunction and Sean and Dr. Benavidez walk right by, with Claire, Wes, Jessup and the crew locked inside a room, unable to catch them.
Claire discovers Minx and Henry were playing and that Henry has gone missing. She leaves to search for him. As she drives away, Wes is informed they have eyes on Sean. Somehow Sean is able to get access everywhere he goes, leading everyone to believe he’s working with someone on the inside. In one of the facility’s buildings, Sean gives Dr. Benavidez the gun, telling her to shoot him if he does something bad. When she points the gun at him, he begins to convulse and falls to the floor. The feds come in and arrest them both. Wes calls Claire to tell her they got Sean, but she is distracted. Finding Henry’s bike, she knows where he’s headed.
Lena is at home watching the news about the power plant when she receives a call from Wes. He tells her that according to Claire, Minx has been at her house playing with Claire’s son all day. Lena tells him that Minx has been in the garage all morning. When he presses her on what Minx was doing, Lena gets defensive but Minx overhears and tells them she made a phone cover, since Wes is always on the phone. At the plant, Dr. Benavidez is fearful that she is being arrested, while Sean is furious and heated. Suddenly the lights flicker and an alarm goes off: the emergency cooling system has failed.
Wes questions Sean, but is getting nowhere – he doesn’t even know his own name. Claire enters the room and can see on a monitor that Henry is walking underneath the cooling towers. She jumps on the monitor to speak with Sean; he doesn’t recognize her at all. The power goes out in Sean’s room for a moment and gunshots are heard. When the power comes back on, Sean is gone. They also discover the reactor is about to melt down and the only solution is to flood it. Henry is still down there in one of the pipes. Claire plans to go back in despite the evacuation, requesting that Wes buy her some time.
While Claire goes in, Sean is roaming the premises when he sees that Henry is in the reactor. Wes talks Claire through the area via a two way radio as she races to find Henry. She finally gets to where she can see him, but she can’t get to him, no matter how much she pounds on the window and cries. Not knowing if he can hear her or not, she apologizes to Wes for everything.
The cool down is swiftly approaching, with water rushing through the pipes. Sean bursts through the door to the room where Henry is and closes the opening to the containment room, saving him. Henry cries out to his father, with Claire witnessing it all. A frantic yet relieved Claire reaches Henry and Sean, embracing them in a family hug. Outside, Wes, Jessup and the crew see the reactor melt and Wes has a meltdown himself. Then, the radiation cloud disappears and the cooling towers are completely normal. Claire, Henry and Sean walk out, completely unscathed.
As the family walks out, the FBI peels Henry away from Claire and capture Sean. When they push him to the ground, Henry yells for them to stop hurting him. Claire, confused by this miracle, learns from her son that Drill fixed him. After getting a call from Wes, a cheerful Lena tells Minx that Wes is coming home and everything is fine. Minx states that she already knew that; Drill said if everyone did what they were supposed to, no one would get hurt. When Lena sees Sean on the TV screen, she says that Drill has been caught, but Minx corrects her: Sean is not Drill.