As revealed in this story, the Thunderbolts are the Masters of Evil: Baron Helmut Zemo disguised as Citizen V; Moonstone as Meteorite; Goliath as Atlas; Beetle as Mach-1; Fixer as Techno; Screaming Mimi as Songbird.
Hallie Takahama adopts a costumed identity (Jolt) and joins the Thunderbolts in this story.
Background is made up of cover images from Avengers (1963 series) #22; 79; 270; 274; 277; Daredevil (1964 series) #140; Incredible Hulk (1968 series) #228 [partially obscured]; Spectacular Spider-Man (1976 series) #16; 49; Captain America (1968 series) #277; 278; Micronauts (1979 series) #25
This story reveals that Zemo's wife died prior to the formation of the Thunderbolts.
This story takes place during Onslaught: Marvel.