MacLaren, his team and their loved ones regroup at a safe house protected by the FBI, but doubts and betrayals may sabotage the rest of their mission.

The team attempts to extract a rogue A.I. from a child messenger, but the program expands too rapidly. A new Traveler adjusts to his host.

Suffering from a fatal brain disorder, Trevor makes the choice to allow himself to be overwritten as the team races to invent an experimental cure.

The Faction sets off nuclear blasts that destroy all of the Travelers' archives, except the one in which a wounded David just happens to be trapped.

Shattered by recent losses and a sweeping new protocol, the Travelers face a bleak future with only one long-shot chance to succeed in their mission.