FANTASTIC FOUR (1961) #268

She-Hulk reveals her origins while taking a tour of the Baxter Building with Johnny. But the tour is interrupted…by a mysterious assailant! While Johnny is showing She-Hulk the Fantastic Four’s trophy room, the mask of Doctor Doom (the only thing left of his explosive end in issue #260) suddenly activates and begins attacking the group. This leaves Reed with the sinking suspicion that Doom may be alive somewhere.