Confusion and fear permeates when one of the children is taken over by Drill, but it isn't clear who it is.

FBI child specialist Claire Bennigan investigates when kids are persuaded to play dangerous games.

Claire talks to a group of kids who have been contacted by Drill; Wes makes a frightening discovery.

While Minx tries to persuade a disillusioned Henry to play one more game for Drill, the race is on for Claire and Wes to thwart John Doe from causing a major incident that could potentially kill millions of people.

Claire and Sean find a man who had a dangerous encounter with Drill more than 30 years earlier.

On the season finale Drill's mysterious endgame is put into motion and the team must do their utmost to stop it before it reaches its final, and possibly deadly, conclusion.

Sean, Claire, Wes and Lena look into the past of the man who first encountered Drill over three decades earlier.

As John pursues his mission, Claire looks into his identity; Drill keeps playing a dangerous game.

Claire has a talk with Sean, who cannot remember her or anything about his past.

Drill sets his sights on a member of the president's family, Sean faces a possible prison sentence for his collaboration with drill; Lena attempts to communicate with drill.