The piece was never finished. It was never inked, let alone scripted or colored. But in 2004, a group of fans got together to complete it. Byrne himself provided his synopsis of the story:
The female Torch is Crystal, but from Counter Earth (which you may recall the High Evolutionary creating in the first WARLOCK).Long-time fans might note how some of the ideas presented here were later used in the creation of Galactus’ herald, Nova. Fans might also note the inclusion of Medusa as a member of the FF, as well as Johnny’s short-lived red and yellow uniform, both of which were the status quo of the team from Fantastic Four #132 until #147.
Basic premise: Altho the H.E. prevented super powers happening on Counter Earth, he did not interfere with the basic genetics, so the strain that produced Medusa and Crystal as Inhumans produced them as mere mortals. The appearance of the H.E. in my story is a flashback to his creation of Counter Earth, and a quick recap of how he shaped events there (with the AniMen interfering and wrecking the "perfect world" he meant to create.) There is also a duplicate Johnny Storm, who meets and falls in love with Crystal there.
Which takes us to the last page. Reed has determined that the female Torch is too volatile to be allowed to remain on Earth, so he decides to duplicate what happened on C.E. when her father (the guy with the beard) launched her into space in suspended animation. Reed swears he will do what he can to find a cure, but offers little real hope. A dejected Johnny (our Johnny) wanders off as Ben observes Johnny is 'the only guy ever to have lost the same girl twice -- on two different worlds!'
The project was finally completed and given the artificial designation of Giant-Size Fantastic Four #1. (The first Fantastic Four Giant that Marvel published was actually titled Giant-Size Super-Stars #1. It was renamed to Giant-Size Fantastic Four with the second issue, meaning that no Giant-Size Fantastic Four #1 was ever actually published.)
Story and Pencils: John Byrne
Script: Mike O'Brien
Inks and Color: F. Ron Miller, Matt Hawes, James Pipik, Darren Taylor, James Stewart, James C. Taylor, Bill Dowling, Stephen Bertrand, Bill Wiist
Letters: F. Ron Miller and Matt Hawes