In the apocalypse of 2163, a desperate Cole searches for Titan. Meanwhile, a captive Railly is faced with an impossible choice as the 12 Monkeys await the arrival of The Witness.

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?

Ramse and Cole splinter to 2007 expecting either a trap - or a final chance to kill The Witness. But when Cole discovers a heartbreaking truth, he’ll discover that the mission was both.

Out of time and in need of answers, Jennifer and Deacon are sent to 1989 to steal the a sacred document. Can Railly and Cole get to the Word first before it reveals the one secret they want kept?

In 1953, Cole and Railly reunite with Agent Gale at the birth of the Army of the 12 Monkeys.

Cole and Railly find themselves at opposite ends of an unspeakable decision. Jones grows suspicious while Railly turns to an emotional ally for advice. All hell breaks loose during a massive fire-fight.

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 battle with the Witness begins.