Dr. Will Zimmerman is convinced that one of his patients, a convicted psychopath, isn't responsible for the murder of two police officers and a room full of people -- an insight that draws the attention of an enigmatic scientist.

Will Zimmerman is faced with the biggest decision of his life when Dr. Helen Magnus offers him a position at her "Sanctuary" for abnormal individuals. John Druitt makes a new and deadly friend.

With the young, murderous child Alexei now in the custody of the Sanctuary, Will must gain his trust before he can be helped. Helen recalls her fateful romance with John Druitt, while Ashley meets with her weapons dealer.

Helen and Will race to a confrontation with John Druitt, who has captured Ashley and revealed the truth about their relationship. Will makes his decision about whether or not to join Sanctuary.