While Wes meets with the President of the United States to discuss what his team has discovered about the mysterious rock, and whether or not it should be destroyed, Drill sets his sights on a member of the president's family.
Claire, Sean, Wes and Lena attempt to unravel the past of a man who first encountered Drill over 30 years ago, which could lead to a way to kill it, before Drill finds a way to murder the man first.
Thinking they might actually be able to defeat this unseen foe, Wes convinces the President to let him round up all of the children in a protected zone in the hopes that Drill will weaken.
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.
One of the children is taken over by Drill, but not everyone is sure which one it is, leading to confusion and fear.