Season 4

Complete listed story — includes the ending

1. The End

In medieval times, a group of Primaries is burned alive by warriors. The sole surviving Primary, a young girl, is entrusted with an ouroboros artifact, and recites Cole's name. In 2046, Cassie revives Jones after her heart stops. Titan splinters in and the temporal facility is attacked. Deacon delays Olivia's forces while Jones's group splinters the entire facility away; Deacon is left behind, and Whitley and Lasky are killed. Jones receives a massive radiation dose. The temporal facility rematerializes under the Emerson Hotel. The time machine is drained of power: Cole proposes to steal a power core from the temporal facility's previous location to repair the machine. Traveling there, Cole sees his past self and realizes Jones's group splintered back to 2043 when they escaped. In 2018 Prague, Jennifer, working with another version of herself, steals the ouroboros artifact from a museum.

2. Ouroboros

In 2043, the Cole, Cassie, and Jones of 2046 infiltrate the temporal facility, taking care not to interfere with their own past timelines. Jones discusses time travel with her 2043 self, then uses the 2043 time machine to send Cassie to 1971, where the latter plans to kill a young Olivia. Cole and Jones then pose as their 2043 selves to steal the power core from the 2043 time machine. In the process, Cole and Jones have emotional conversations with 2043 Ramse and 2043 Whitley, respectively. In 2018 Prague, Bonham, an Interpol agent, investigates Jennifer's theft of the artifact. Jennifer learns her Primary abilities are gone, and her alternate personality vanishes. While attempting to flee, she is intercepted by Bonham at a train station; the latter reveals his knowledge of the 12 Monkeys. In order to escape, Jennifer throws herself into the path of an oncoming train.

3. 45 RPM

In 1971, teenaged Olivia has apparently abandoned the Army and is on the run from her mother, Mantis. She lives with a friend and is surviving by theft. Mantis and her protectors find her; she escapes but is caught by police and held in a cell. Cassie, in 1971 to kill Olivia, is involved in a shootout while spying on her and is caught by police; she is put in a cell next to Olivia's. It is revealed Olivia is pregnant. Cassie tries to help her change her fate by talking to her as a mother. It is revealed Olivia was devoted to the Witness all along, and it was her mother who was trying to remove her. Cassie shoots at Olivia, but Mantis steps in to take the bullet. Olivia's child is born and left near a tree in a forest. In 2018, Future Cole saves Jennifer from the oncoming train. He warns her that Present Cole is coming to meet her. Cole and Jennifer get the Ouroboros back from the Interpol agent, and Cole opens it by remembering the story from his childhood. Inside, he finds a slip of paper with the notation "Blackleaf 1852": the next mission. Cole reunites with Cassie at the Emerson Hotel and assures her they will break the loop. At Titan, Deacon is dug out, still alive and angry at being left behind. Olivia kills Mallick, and Deacon becomes her new right-hand man.

4. Legacy

Cole, Cassie, Hannah, and Jennifer splinter to Blackleaf, Montana in 1852. There, Hannah recognizes her father, Dr. Elliot Jones, and the team learns that Elliot is working with the Pallid Man and the Army to construct the main tower of Titan in Blackleaf. Hannah splinters back to 2043 with Elliot to the Project Splinter facility where Elliot and Jones deduce that the Army plans to use the Titan to create a paradox to destroy time and create the Red Forest. Cassie figures out that Jennifer has lost her "Primary" abilities. Cole, Cassie, and Jennifer encounter Tihkoosue of the Siksika who tells them about a weapon that past Primaries made to destroy the Witness. Despite Tihkoosue's warning, Jennifer takes a drink to speak to the old Primaries about the weapon, revealing the team's time and location in Blackleaf to Olivia along with the existence of the weapon. Elliot and Hannah splinter back to Blackleaf and the team devises a plan to destroy the power cores for Titan. Olivia sends Deacon to Blackleaf and foils the plan. Before being killed by Deacon, Elliot manages to steal the designs for Titan and give them to Hannah. The team splinters back to the Project Splinter facility where Cole reveals that the story from his childhood about the weapon came from Cole's mother. In the early development of Project Splinter's time machine, Elliot's assistant Emma is revealed to be a member of the Army as well as Olivia's daughter.

5. After

In 2043, Jennifer searches the FBI database for the message "Climb the Steps, Ring the Bell" which she believes is a clue to finding the weapon that can be used against the Army. After her search uncovers a picture of the message written on the wall of a motel room in 1966, the team believes that Soviet spies are attempting to buy the weapon. Cole and Cassie splinter to 1966 and attempt to obtain the weapon. The Army interferes and poisons Cole. Cassie splinters to 2043 and then back earlier in 1966 to warn Cole. Jennifer also splinters to 1966 to help save Cole with the help of FBI agent Robert Gale, who is revealed to have prevented his own death in 1961. Jennifer figures out that the message on the wall was actually written by herself. Cassie, Jennifer, and Gale succeed in saving Cole. Working for the Army, Deacon obtains a case believed to contain the weapon, but he implies to Jennifer that he has actually not switched sides. Gale provides information to the team that leads them to believe that the Ahnenerbe, an SS organization in Nazi Germany, uncovered the weapon during World War 2. Through a conversation with the Pallid Man's father, Cassie begins to believe that the creation of the Red Forest may be the only way she and Cole can be together.

6. Die Glocke

In 1940 France, a Nazi SS officer acquires a manor and holds a gala for exhibiting artifacts collected by the Ahnenerbe. One of those artifacts is "Die Glocke" which the Project Splinter team believes is "the bell" referenced in the clue "Climb the Steps, Ring the Bell." Cole, Jones, Cassie, and Jennifer splinter to 1940 with a plan to infiltrate the gala and obtain Die Glocke. Deacon also splinters to the gala and joins the team, revealing that he is still on Project Splinter's side despite ostensibly working for the Army. The team encounters French Resistance operatives who plan to use a bomb to assassinate Adolf Hitler, who will be attending the gala. Although their plan is complicated by the Resistance's efforts, the team manages to obtain Die Glocke. Deacon and Jennifer also kill Hitler by detonating the Resistance's bomb. It is revealed that the case Deacon obtained in 1966 contained a useless artifact. Upon examining Die Glocke, the team discovers the message "1491, Hertfordshire, England." In 2043, Deacon and Jones agree to allow Deacon to maintain the appearance of working for the Army by capturing Jones and delivering her to Olivia.

7. Daughters

Emma is brought to 2043 to complete Titan while Jones sends Hannah on a mission to 2007 with a sealed letter that is to be opened on March 8, 2009. In 2043, Olivia psychically interrogates Jones, trying to obtain the location of the Primaries' weapon. Jones finally confesses that it is in 1491 England, and Olivia orders Titan to splinter away to that time. It is revealed Jones confessed deliberately so that Adler could use Titan's temporal signature as a beacon to splinter Jennifer, Cole, and Cassie to 1491. In 2009, Hannah opens the letter and learns her mission is to find Marion Woods, Cole's mother. She rescues Marion from the Army's assassins and discovers Marion is Emma. It is then revealed Emma abandoned the Army after completing Titan and fled to 2009. In 1491, Olivia sends Deacon out to search for the weapon and reveals to Jones her knowledge of Deacon's duplicity, threatening to kill him and everyone she loves.

8. Demons

In 1491 England, Andrus, a rogue Primary who has allied with the Army, helps Olivia search for the Primaries' weapon and kill the Primaries who created it. Jennifer is imprisoned as a witch but is freed by Cole and Cassie. They meet with Nicodemus, a scholar who created the ouroboros artifact. Nicodemus reveals that Jennifer retains her Primary abilities; the Primaries simply chose not to communicate with her for a time to avoid alerting Olivia of their plans. Nicodemus shows them the location of the weapon, which turns out to be a time machine. They ring Die Glocke, activating the machine, but Olivia and Andrus arrive, disabling it. Olivia kills Deacon, but before she can kill the others, Adler manages to send a personal time machine to Cole from 2043. Cole, Cassie, and Jennifer use it to escape to 2043, however Olivia destroys the weapon with a massive temporal paradox, ensuring Deacon's permanent death and rendering the weapon inaccessible for all time. In 2043, older Jennifer advises her younger self to begin listening to her Primary visions again.

9. One Minute More

In 2043, Jones's group try to decipher Jennifer's final message from the Primaries. Jones realizes that the message contains the dates of all their splinter voyages, and one date to which they have not traveled: 2018, just before the plague's release. Cole and Cassie splinter to 2018 and steal the plague virus from the Army, planning to destroy it. They encounter Hannah at the Emerson Hotel, and realize that the Primaries actually intended them to initiate the plague to ensure time travel would be developed by Jones. As they prepare to release the plague, one of Olivia's agents tries to kill Cole, but Hannah sacrifices herself to save him, and Cassie reluctantly chooses to release the plague in order to ensure causality. Cole finds a letter from Hannah that reveals she is Cole's mother: she and Emma were attacked by the Army and sought help from Cole's father; Emma was fatally wounded, and Hannah took the name of Marion and fell in love with Cole's father, leaving Cole with him to protect him from the Army. Cole and Jones splinter to 2017 to enjoy one last moment as a family with Hannah. Jones deduces she was mistaken about the Primaries' message and that the purpose of their weapon was to erase Cole from all time so that the proper causality could be restored. Olivia initiates the Red Forest paradox.

10. The Beginning Part 1

The group realizes that they need to load the Primaries' program into the Project Splinter time machine to erase Cole from time entirely. Cole uses a personal time machine to splinter back to 2163 as his past self finds Titan and rescues him, then splinters to 2018 to rescue Jennifer as she falls onto the train tracks. After he returns, he finds out that their computers will never be able to compile the Primaries' program before the Red Forest paradox destroys time. However, Titan's computers can, so Cole decides to take it over. He retrieves Ramse from just before he dies and recruits him to their cause. Jones then splinters the entire temporal facility into Titan, and the group launches an all-out assault.

11. The Beginning Part 2

A massive battle breaks out between Jones's group and the Army of the 12 Monkeys, with the Daughters and the West VII soon joining in. Cassie confronts Olivia and, after a fight, shoves her into a temporal energy beam, splintering the upper half of her body into the distant past, where it becomes the corpse from which the virus originated. Cassie nearly lets time collapse so she can be with Cole forever, but Cole talks her out of it, and she stops the countdown before the Red Forest paradox initiates. Ramse, Jennifer, and Cassie are sent back to their own times while Cole and Jones share a last conversation before Jones dies. Cole loads the Primaries' program into the time machine and activates it, erasing himself from time. A new timeline is created in which time travel is never invented. James Cole, the virus, and the Army of the 12 Monkeys never come to exist, and everybody else lives a different life. Cassie, however, remembers what happened. Cole finds himself on a beach, where Jennifer tells him that Jones modified the program to reinsert him into the new timeline. Cole and Cassie each find their way to the farm house where they once lived together, and the two begin their hard-earned happy ending.