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.

Cole's search for the location of the virus leads him to 2014, and to a devastating moment in Dr. Railly's life involving a dangerous outbreak in Haiti.

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 Dr. Railly face off with the Army of the 12 Monkeys when both discover the Night Room –- an off-site, black ops lab that houses the virus that will one day destroy the world.

The Core that powers the time machine is fading. To get Cole back from the past, Jones must convince her former colleagues at the military operation "Spearhead" that her mission is worth saving.

Cole finds himself in 2017 at the height of the plague. Out of options, Jones faces an impossible choice to replace the Core.

Cole gets stranded in 2016 after an attempt to destroy the virus changes the future. Jones and Railly deal with the consequences of the changed timeline.

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.

In the present, Cassie and Jennifer Goines run from the 12 Monkeys; in 2044, Cole and Ramse face off against Deacon.

Jones comes to the disheartening realization that time travel is humanity's true enemy and that as its architect she needs to be stopped, and so she sends Railly back to the year 2020 with orders to undo all of it.

Cole has his loyalty tested when Ramse and Railly go rogue, embarking on an unsanctioned mission that sends them to 1961 East Berlin. Once there, they have murder on their minds as they search for an unscrupulous German doctor who knows the location of "The Witness."

With the temporal facility on the verge of destruction, Cole and Jones find themselves in the middle of a coup. After a violent encounter ends in an unexpected tragedy, Cole is sent back to 1957 in a last-ditch effort to save humanity while the rest embark on a caravan across the apocalypse to find Titan -- the stronghold of the Witness.

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?

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 final battle with the Witness begins.

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.

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.