Giant-Size Fantastic Four #4
Madrox the Multiple Man
While taking the subway to a football game with Alicia, the Thing's plans are ruined when Ben has to deal with somebody in a strange costume standing on the tracks. Surprisingly when Ben strikes this man, he turns into two more, and multiplies with each blow. Ben is eventually overpowered and knocked out in a battle. The rest of the Fantastic Four arrive and revive Ben, but the "Multiple Man" is nowhere to be seen.
The Multiple Man turns out to be Jamie Madrox, a mutant who had the power to create duplicates of himself. However, he had no control over these abilities and so his parents built a suit that would contain and allow him to control his powers. However, his parents died six years ago and after living that time in solitude, Madrox has found that his suit has begun to malfunction and this is what has brought him to New York City.
The Fantastic Four track down Madrox and battle him, however his duplicates prove to be too powerful for them to deal with. It's not until the intervention of Charles Xavier (A colleague of Jamie's father) arrives to lend a hand. Xavier explains to Reed Richards of the situation, and while the team battles Madrox and his doubles again, Charles uses his mental powers to stun them all. Reed then uses his stretching powers to get close enough to the real Jamie Madrox and correct the problem with his containment suit. The process leaves Madrox unconscious, Charles then tells the Fantastic Four that he will take Jamie into his care and cure him of his madness.
Recurring Characters
Fantastic Four (Mister Fantastic, Medusa, Human Torch, Thing), Alicia Masters, Professor X, Multiple Man, Daniel Madrox, Joan Madrox
Continuity Notes
Ben and Alicia are going to a New York Jets football game, and the Thing makes a reference to wanting to see Joe Namath play. Namath was a member of the Jets from 1965-1976 before being traded to the L.A. Rams in 1977. He retired from the National Football League after that season. This should be considered a topical reference per the Sliding Timescale of Earth-616. As Namath was still playing for the Jets at the time this story was originally published.
Here the members of the Fantastic Four appear to be oblivious to the fact that Xavier is a mutant with telepathic powers. At the time Xavier's mutant powers were a secret to the world in general, but this contradicts later tales that reveal that the Fantastic Four were aware that Xavier was a mutant and leader of the X-Men. The earliest chronological proof of this was in a story depicted in X-Men First Class (vol. 2) #1, which took place shortly after the wedding of Reed and Sue in Fantastic Four Annual #3. Provided you consider First Class part of continuity like I do.