The Marburg virus has apparently run its course. Several months after the death of his wife and a nervous breakdown, Frank rejoins the FBI and investigates a plane crash with a new partner.

Frank and Emma investigate a family of identical women who are apparently being killed off.

Frank and Emma investigate a survivalist group worried about the Y2K bug.

Frank and Emma investigate a mass grave that may have links to the Millennium Group.

Emma tries to help her drug addicted sister and learns that local addicts are exhibiting strange mutations linked to tainted heroin.

Frank and Emma investigate the suicide of a former FBI agent and discover links between the FBI, the Millennium Group, and the Los Alamos nuclear research center.

Frank and Emma attempt to locate a girl who escapes from a mental institution while Emma's father grows ill.

Frank investigates a series of murders that replicate a serial killer case from his past while Emma moves closer to the Millennium Group.

Frank is held responsible for a man's death while Emma joins with the Millennium Group.