- X-Men (Main story and flashback)
- Cyclops (Scott Summers) (Main story and flashback)
- Wolverine (Logan) (Main story and flashback)
- Rogue (Main story and flashback)
- Gambit (Remy LeBeau) (Main story and flashback)
- Beast (Hank McCoy) (Main story and flashback)
- Storm (Ororo Munroe) (Main story and flashback)
- Morph (Apparent death) (Main story and flashback)
- Jean Grey
- Professor X (Charles Xavier)
- Jubilee (Jubilation Lee) (Joins team)
- Mutant Control Agency
- Mister Sinister (Nathaniel Essex) (Behind the scenes)
- President of the United States (First appearance)
- Senator Kelly (Appears on a computer screen, TV, or hologram only)
- Martha (Jubilee's foster mother)
- Jubilee's foster father
- X-Men Blackbird (Main story and flashback)
- Wolverine's Jeep (First appearance)
After breaking into the headquarters of the Mutant Control Agency and destroying the mutant files, the X-Men lose two of their own members in a battle with the Sentinels: Beast is captured and imprisoned, and Morph is killed by a Sentinel. Wolverine demands to go back for them, but is prevented by Cyclops and Rogue - he later vows to avenge Morph's death. Meanwhile, Henry Gyrich interrogates a captive Jubilee at his Sentinel-manufacturing facility in Detroit, Michigan.
The President of the United States - an unnamed woman - publicly announces the X-Men's raid on the "Federal Security Agency" headquarters, and the existence of the Sentinels. Locating Wolverine at a bar, Cyclops asks him to help find the Sentinel's home base. The president orders Gyrich to close down his privately-funded Mutant Registration Programme, concerned that the X-Men might have had good reason to destroy Gyrich's mutant files. Jubilee's foster father calls Gyrich, telling him that Cyclops is in his house, and Gyrich asks him to keep Cyclops at home as long as he can. However, Jubilee's foster father decides to warn Cyclops after his wife tells him the information Cyclops mentioned to her that Jubilee was likely to have been kidnapped by the Sentinels.
A Sentinel attacks Cyclops as the leaves the house. Cyclops fights back, by purposely blasting it's arm off, so the damaged Sentinel could return to base for repairs with the X-Men following it in the Blackbird. They destroy all the Sentinels present and rescue Jubilee, but Gyrich and his manufacturer, Bolivar Trask escape. Jubilee bids farewell to her foster parents, and moves into the Xavier Institute.
- The opening scene of this episode is a duplicate of the end of the previous episode.
- Names listed on the "Mutant File" screen: Michael Booton, Geri Bryan, Andy Hamilton, Chris Hamilton, Ray Sherman, Corbin Went, and John Wesley.
- The death of Morph, whose Earth-616 counterpart Changeling also died serving the X-Men (while posing as Professor X). However, the reaction to Morph's death was much more in line with the death of Thunderbird in X-Men #95.
- The sequence wherein Jubilee arrives at the X-Mansion is based on a similar sequence when Kitty Pryde first arrived at the X-Mansion following the funeral for Phoenix in X-Men #138.