A boy named Nicholas overhears his parents arguing about him. Alone in his room, he sits on his bed when all of a sudden the lights of his electronic toy flicker. Nicholas begins to have a meltdown, telling the voice inside his head to stop. Hearing his screams, his parents rush into his room and he explains to them that the voice wants to be his friend: it’s Drill. In the Lawrence house, Wes (Barry Sloane) watches Minx (Kylie Rogers) on a thermal security camera, while at the Bennigan house, Claire (Lily Rabe) and Sean (Milo Ventimiglia) are concerned for Henry (Kyle Harrison-Breitkopf). In the middle of the night, Drill attempts to contact Minx, who turns him down. Minx informs her parents Drill is willing to forgive them, as long as she helps him make a new friend.
Claire, Sean, Wes and Lena (Kristen Connolly) meet to discuss their children’s safety from Drill. They decide on taking on Drill by profiling him much like a killer. Henry and Minx interrupt their parents’ conversation; Henry tells Claire and Sean that he doesn’t feel well. Sean volunteers to take him to the doctor. Claire and Jessup (Derek Webster) investigate out-of-the-ordinary energy consumption in the area, discovering strange brownouts at specific locations.
Nicholas is targeted and attacked by a group of boys on the playground, but Drill comes to his rescue. The boys disperse and a grateful Nicholas makes a deal with Drill. Claire and Wes take their information to figure out how to outsmart Drill. Lena interrupts to inform Wes she’s afraid and she’s taking Minx on a cruise to escape until Drill is contained. Claire, Wes and Frommer go on the offensive to catch Drill after learning that he is getting weaker. Their plan: to shut off the power grids around the city, cornering him in an abandoned school where they will finally shut the power off and wait for him to expire.
Stealing vital information from his parents’ safe, Nicholas goes to the abandoned school to meet Drill. Meanwhile, Sean is stuck in traffic due to the citywide blackout while driving Henry back from the doctor. Henry senses Drill: he’s here. When the lights go out on the street, Sean attempts to avoid the traffic and chaos, driving on the sidewalk and into an alley. Once they cross to the road, it seems that they’re home free – until a car suddenly approaches and crashes into them. Meanwhile, Claire, Jessup and Wes locate Drill inside the abandoned school and shut off the power.
In their crashed car, Sean comes to and realizes Henry is passed out -- and pinned into his seat. A stranger arrives, however, and helps to rescue Henry. At the boarding dock, Minx tells Lena she doesn’t feel right about leaving Wes behind. Lena changes her mind about the cruise at the last minute and returns home. Outside of the school, Claire and Wes notice a child in the window of the school: it’s Nicholas. Frommer orders them to stand down, but Claire and Wes go against his wishes and into the school to save the boy.
Inside the school, Claire and Wes run after the boy; when they finally catch up to him, Drill begins painfully possessing Nicholas. A kind stranger gives Lena and Minx a ride back home, asking many questions about Wes. The president finally orders the grids back on, saving the child, yet letting Drill escape. Later, Frommer tells the president he doesn’t think the president made the right call. Sean and Henry make it home safely, as do Lena and Minx. Lena calls Wes to inform him they didn’t leave – it looks like their relationship is getting back to where it’s supposed to be.
Outside in his car, the kind stranger scribbles names into his notepad. It already lists Sean, Claire and Henry -- who is this man? Inside the Lawrence home, Lena makes her way into the kitchen while the refrigerator water dispenser is running. Stepping into a puddle of water, she is electrocuted. Wes comes home to find Minx standing outside, staring blankly ahead. He tries to ask her what’s going on, she doesn’t respond. He rushes inside, calling out for Lena, only to find her dead body lying on the kitchen floor. He cradles Lena’s body and sobs uncontrollably.