Walter thinks the abduction of a young music prodigy is linked back to his old bunkmate at St. Claire's Hospital. When he kidnaps the child he sees a sequence of flashing lights. Olivia wants Walter to return to the mental institution much to Peter's outcry, but Walter's determination to help ends up having chilling ramifications.

Setting the stage for the dramatic and revealing first season finale are a sudden and unexpected attack on someone with close ties to Fringe Division, the return of bioterrorist David Robert Jones and the inexplicable disappearance of Walter. Find out more about the mysterious events surrounding our trio when questions are answered, observations made, loyalties are tested and the elusive William Bell is finally introduced.

A teenage girl pronounced brain dead wakes up in the middle of the operation to remove her organs... speaking numbers in Russian. When the Navy confirms that the numbers are nuclear launch codes and a missing officer named Rusk knows them, the search is on for the missing man.