- Bishop (First appearance)
- Wolverine (Logan) (Earth-31393) (Only appearance)
- Forge (Only appearance)
- Unidentified electrokinetic female mutant (Only appearance)
- Unidentified metal armed speedster male mutant (Only appearance)
- Protestors (Future, Bishop's memories)
- Anti-mutant campaigner (Future, Bishop's memories)
- Mutant prisoners (Future, Bishop's memories)
- Human soldiers (Future, Bishop's memories)
- President of the United States (Future, Bishop's memories)
- Assassin (Photo)
- Earth-31393 (First appearance)
- Temporal Transceiver (First appearance)
- Time Portal (First appearance)
- Bishop's gun (First appearance)
- Cyclops' Visor
In a dystopian future, a mutant Tracker named Bishop hunts other mutants for the ruling Sentinels. When he reaches his quota, however, the Sentinels turn on him. With help from the mutant rebels, he travels through time back to the present in order to stop a member of the X-Men from assassinating someone. However, he cannot remember who the assassin is, and sets out to kill the X-Men. Wolverine subdues him and Professor Xavier scans his mind with Cerebro. The super-Sentinel Nimrod follows Bishop back in time, and the X-Men unite to fight it off. Bishop destroys its temporal transceiver, sending it back to the future. Bishop remembers that Gambit is the assassin, drawing his gun and firing.
In a dystopian future in the year 2055 AD, Wolverine and two unnamed mutants battle the Sentinels. A mutant Tracker named Bishop attacks the three mutants and takes them to a mutant termination center. Wolverine tells Bishop that the Sentinels want to kill all mutants, not just the rebels. Bishop shrugs this off, saying they treat the rest of the mutants just fine. However, when the Sentinel informs Bishop that he has reached his quota and is no longer needed.
Wolverine and Bishop carry the two mutants into the center, escorted by a Sentinel. Wolverine notices the graves of the former X-Men. The two mutants take down the Sentinel and Wolverine finishes the job. The super-Sentinel Nimrod flies into the scene. The female mutant reminds Wolverine of the mission and urges him to go. Bishop and Wolverine arrive at a rebel hideout, where they meet Forge.
Wolverine plans on using the temporal transceiver to go back in time to the '90s to stop an assassination. Forge says the rebels have a theory that if the assassination never occurred, then the dystopia would have never happened. Bishop volunteers to go instead, and Forge backs him up. The Sentinels and Nimrod attack the hideout as Bishop goes back in time.
Bishop finds himself in an alley and soon learns that the time travel worked, although he can not remember much about his mission. Rogue and Gambit visit Beast in his jail cell. Gambit says he does not understand how Beast can stand living in a cell. Bishop studies his transceiver and deduces that he must have been sent back in time to stop the assassins, the X-Men. Bishop steals a bus and drives it into the X-Mansion and starts attacking Storm and Cyclops. Wolverine stops Bishop and prepares to kill him. Professor Xavier stops him and scans Bishop's memories of the future. The X-Men, especially Wolverine, do not trust Bishop's story at first.
The transceiver warns Bishop that something has come back through the time portal. Bishop and the X-Men investigate the residual energy from the portal and encounter Nimrod. The Super-Sentinel attacks the group. Jean and Jubilee try combining their powers to attack Nimrod, but he attacks both of them. Storm summons the elements and freezes Nimrod's super structure. The rest of the X-Men attack the Super-Sentinel, making it fall into pieces. As Nimrod reassembles, Bishop takes out its temporal transceiver, making it go back to the future. The X-Men gather and discuss who the assassin could be. Rogue and Gambit return, and Bishop remembers that Gambit is the assassin. Furious, Bishop draws his gun and fires.
- In the future reality depicted in this episode, Wolverine walks past graves of the old X-Men:
- Cyclops, d. 2032
- Rogue, d. 2033
- Storm, d. 2021
- Jubilee, d. 2010
- Other graves are seen, but the inscriptions cannot be discerned.
- The President seen in Bishop's memories, weeping as the Sentinels take control, is the same woman from "Night of the Sentinels (Part 2)" who told Gyrich to close down the Sentinel program.
- The two teenage mutant rebels who assist future Wolverine on "the mission" at the beginning of this episode are a red haired girl who can fire white light energy from her hands, and a boy who can transform his arms into organic steel, seemingly giving him super strength.
- The mutant file on the Sentinel scan for Bishop's card is 051063-241, the same as Jubilee's in the first episode.
- While visiting Beast in jail, Rogue gives him a copy of You Can't Go Home Again by Thomas Wolfe, which he identified as an "old favorite". The book explores themes about the passage of time, which is appropriate to the episode.
- Beast quotes the poem To Althea, from Prison when he says, "Stone walls do not a prison make, nor iron bars a cage."
- Two children that walk by Bishop have a new cartridge video game called Assassin. The picture on the cover resembles the Punisher (Frank Castle). This is a reference to the original name that creator Gerry Conway conceived for the character before Stan Lee suggested he change it to Punisher.
- Wolverine refers to Bishop as "Mister Terminator", a reference to the Terminator character from the Terminator film series, who also traveled back in time from the future to kill somebody and alter the timeline.
- This episode is loosely based on X-Men #141, the first part of the Days of Future Past story arc. The entire story was retooled to fit the continuity established in the animated series, however some original elements remained:
- Much like his Earth-811 counterpart, Wolverine led a resistance against the Sentinels.
- Bishop's role as a tracker of Mutant rebels is reminiscent of Rachel Summer's role as a Hound, likely adapted from Uncanny X-Men #189.
- Similarly, Bishop's betrayal of the Sentinels and travel back in time is adapted from Kate Pryde's similar stunt in X-Men #141.
- Nimrod's appearance and battle with the X-Men is likely adapted from Uncanny X-Men #191 and 194.
- Bishop's assertion that Gambit betrayed the X-Men is adapted from Uncanny X-Men #287 wherein Bishop's future the X-Men were apparently killed by one of their own, and as Gambit was the only survivor Bishop long suspected him of betraying the X-Men.
- Forge's role as the leader of the Resistance seems to be an adaptation of the fan theory that the unidentified leader of the Xavier's Underground Enforcers, who debuted in X-Factor #140 was none other than Forge.