The final conflict with the Army of the 12 Monkeys begins when the Witness returns to Project Splinter.

Travelers come face to face with ghosts from their past when they find themselves maneuvering around their own timelines.

Cassie travels back in time to confront a younger Olivia; Cole helps Jennifer find the meaning behind her final Primary vision.

Team Splinter goes back in time to the wild, wild frontier in search of a weapon to destroy the Witness.

A clue to breaking the cycle leads Cole and Cassie to the 1960s. Christopher Lloyd returns as Zalmon Shaw, a devoted follower of the Witness.

The team infiltrates a Nazi gala to steal an artifact known as 'Die Glocke'. Their operation comes undone when French Resistance interferes and an unexpected guest arrives.

Jones sends Hannah back in time to 2007 on a personal mission that could be the key to everything.

Everything changes when the team finally climbs the steps... and rings the bell in the Middle Ages.

The final battle against the Witness as the fate of time and mankind hangs in the balance. All the pieces finally come together to mark the end of the beginning.

When all hope is lost, Cole must complete his cycle so that his younger self will one day arrive at the end with the answer.