Sue Storm, stranded deep in the future at the end of Earth's history, is the last thing alive on the once-vibrant world. How can she make it back to her proper time before being killed? Meanwhile, Reed Richards, stranded in Earth's past, waits for a rescue from her that will never come... unless there's some way their relationship — the deep and loving understanding this man and woman have for each other — can transcend time itself... Meanwhile, in the present, Doom reveals precisely how he's managed to stymie the Fantastic Four for so long: a secret to his invincibility that has transformed every loss into a win! And it's one that makes Emperor Doom invincible... LEGACY #728