In the year 2055, mutants are hunted by Sentinels. They are nearly extinct, as are the X-Men. An aged Wolverine fights with other rebel mutants against the Sentinels. Bishop, a former tracker, now fights alongside the rebels. Wolverine takes Bishop to see Forge, who is an expert on machinery. There is a theory that if Senator Kelly from the 1990s was not assassinated, mutant slavery will not happen. Bishop is sent to the past to stop the assassination.
After arriving in the past, Bishop’s tranceiver tells him to seek out Charles Xavier and the X-Men. He breaks into the mansion and receives a less than warm welcome from the X-Men. Xavier uses Cerebro to probe Bishop’s mind. After seeing grim visions of the future, Xavier decides to help Bishop in his quest. Bishop informs the X-Men that the assassin is an X-Man, though he recognises the face, he doesn’t know the name.
Bishop takes the X-Men to the point where he arrived via a time portal. Wolverine is still sceptical of Bishop and pounces on him every chance he gets. They are interrupted by a Sentinel from the future, an advanced model called Nimrod, who has followed Bishop.
The X-Men defeat Nimrod, and Wolverine is more or less convinced that Bishop is telling the truth. When they return to the mansion, they are greeted by Rogue and Gambit who have returned from visiting Beast who is in jail after the X-Men’s infiltration of the Sentinel facility where he, with Morph, were left behind.
Bishop immediately recognises Gambit as the assassin and proceeds to open fire at him.