The Flash: Terminal Velocity (The Flash (1987) (Old Editions) #3)

In FLASH: TERMINAL VELOCITY, the Flash must confront his own humanity and future as he tries to save the life of the woman that he loves and thwart the devious plot of a maniacal madman. After learning that the Speed Force, the source of his powers, is slowly augmenting his abilities while pulling him into another plane of existence, the scarlet speedster must find a way to escape his vision of his impending death. But when he is caught in a no-win situation, the fastest man alive sacrifices himself to stop the super-villain Kobra from taking over Keystone City by pushing his powers to the limit and selflessly disappearing into the Speed Force forever.