Olivia begins to regain her memories of her encounter with William Bell. Meanwhile, the "First Wave" tries to collect the head of their leader, and the traitor makes his move.

Two men kidnap a teenage boy using mind control abilities. The boy's father works for Massive Dynamic but Nina insists that the company hasn't been developing mind control, and has no idea who the two kidnappers are. The truth or falsehood of her statements are soon confirmed when Peter encounters the person responsible for the boy's abduction.

When a scientist falls dead after ingesting a lethal cloud of blue powder and his bones disintegrate in his body, the CDC suspects a biological attack. As the Fringe Team investigates further, a subject from Walter's past with ties to Olivia reluctantly agrees to assist with the intense case.

As the Fringe team investigates a mentally ill patient who appears to be connected to a series of murders, frightening clues and connections are uncovered that lead Olivia to some shocking revelations.