A young nurse carelessly lets go of her baby's carriage, on a steep hill. The baby carriage rolls straight for an enormous mirror. At the last second, before impact, Kid Flash grabs the carriage, and vibrates it's molecules, as well as his own, into intangibility. Though Kid Flash, and the baby carriage, pass through harmlessly, the mirror, nonetheless, shatters. The two men holding the mirror were so awestruck at Kid Flash's spectacular rescue, that they accidentally drop the mirror.
Kid Flash, as Wally West, arrives at the church, where his uncle, police forensics scientist, Barry Allen, is to wed Fiona Webb. West finds that Allen has seemingly left Webb at the altar. In reality, Allen, as the Flash, is currently fighting a running super-speed battle, across the world, with his nemesis, Professor Zoom, the notorious Reverse Flash. The wedding guests begin to fear the worst for Allen. Police Captain Darryl Frye believes it's time for the police to look into the matter.
West and Ralph Dibny, the world famous Elongated Man, speak with Allen's father, Henry. West is just about to search for Allen, as Kid Flash, when he is stopped by one of the Guardians Of The Universe. The Guardian has vowed to allow the Flash to face his enemy alone, and will brook no interference in their conflict from West, or anyone else. To taunt his foe, Professor Zoom carves a massive effigy of Iris West Allen, in the side of a mountain.
The sight of his dead wife, a woman murdered by Professor Zoom, incites a seething rage in the Flash. Racing at super-human speed, Professor Zoom generates sonic booms that trigger a massive rockslide. The Flash burrows underground for cover. Professor Zoom and the Flash continue their epic battle, underground, ranging from the Himalayas to Miami Beach. To distract his foe, Professor Zoom generates a tidal wave, in Florida. Frye issues an all-points-bulletin to find Allen.
The Flash chases Professor Zoom, onto a rocket, being launched into space from Cape Canaveral. After vibrating the rocket to pieces, the Flash follows Professor Zoom back to Earth. Professor Zoom speed-writes his intention to murder Webb in the sand. Webb finally accepts the fact that Allen is not coming. The Flash races faster than he ever has before, to prevent Professor Zoom from murdering Webb. Just as Professor Zoom is about to vibrate his hand into Webb's brain, the Flash tackles him, snapping his neck. The Flash consoles Webb. Frye inspects Professor Zoom's body, declaring that the Reverse Flash, is, in fact, dead.