The trail of a mysterious organization called the “Army of the 12 Monkeys” leads Cole to a mental institution in 2015, where a patient holds the key to the plague that destroys the world. Meanwhile, despite warnings that her involvement may disrupt the course of history, Dr. Railly risks her life to help him.

A fight for the future ensues when a dangerous band of marauders hunting for Cole and Ramse threatens the mission to save the past.

Cole and Railly attempt a final confrontation with their closest enemies, while Jones faces a new threat to all that she's accomplished.

Cole and Ramse repair their broken friendship while on the run; Railly and Jones navigate an uncertain future in 2043.

Despite the growing tension between them, Cole and Cassie time travel to New York during World War II to track down a dangerous member of the Twelve.

When Cole and Cassie are stranded in 1944, Jones must turn to the person she trusts the least to bring them home -- Ramse. For Ramse, this mission will give him a chance to atone for his sins -- but can he mend the broken relations between Cole and Railly? Meanwhile, Jones visits Old Jennifer Goines to explore the true nature of Time - and the Twelve’s method to destroy it.

Cole and Railly attempt to stop the final paradox in the past while Ramse, Jennifer and Deacon struggle to survive the apocalypse in a last ditch effort to find the Witness.

Cole and Railly have finally found peace living in the past. When a mysterious woman with apocalyptic visions of the future tells Cole it's not over, he must do the unthinkable to save the world... and the woman he loves.

While searching for Jennifer Goines in post-WWI France, Cole and Jones encounter a dangerous group of time- travelers - the Guardians.

Bonds of trust are tested when Ramse returns to the facility with an old enemy held captive. How far will Cole and Jones go for the answers they need?

Former friends, now enemies, race to find the Witness in 1904, who, at last, reveals his face.

The reason why the Witness wants to destroy time and all reality is revealed.

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

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.

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

The beginning of the end as Cole and Cassie embark on their final mission.