As Barry and his partner, Frank Curtis, get closer to finding the drug dealers in Central City, the Reverse-Flash returns to send Barry on a dangerous chase.
Police forensics scientist, Barry Allen, has just received word, from Detective Frank Curtis, that deranged murderer, Clive Yorkin, did not kill Allen's wife, Picture News reporter, Iris West Allen. While Allen is processing this news, he hears a gunshot. Curtis has been gunned down by drug dealers. Allen races to Curtis' rescue, as the Flash. As the gunsels move in on Curtis, he suddenly bolts up and begins shooting. Curtis manages to kill three of his assailants, before he is cut down by machine gun fire. Arriving on the scene, the Flash begins clapping, at faster and faster speeds. The resultant sonic vibrations fell the remaining gunmen.
Attending to Curtis, the Flash sees that all but one of the gunshots were caught by Curtis' bulletproof vest. The Flash gets Curtis to the hospital. News of Curtis' survival reaches the chief of police, Harvey Paulson. The Flash, as Allen, walks in on Paulson, during a phone conversation. Paulson has all but revealed that he is the man behind the multiple assassination attempts on both Curtis, and Allen. Paulson is uncertain how much of his conversation Allen overheard, but, nonetheless, makes plans to flee the city. Curtis shows Allen a videotape of Allen's wife's murder. Allen watches as West Allen is confronted by Yorkin.
Something just out of sight of the camera, attracts West Allen's attention. West Allen falls to the ground, dead. Spooked by whatever caused her death, Yorkin flees. Allen is stunned, and breaks down in tears. His wife's murderer is still at large. At her gravesite, Allen vows to bring her murderer to justice. A police bulletin alerts Allen to a shoot out between the police and a group of gunmen, at the powdered milk factory. Allen races into action, as the Flash. Arriving on the scene, the Flash is surprised to see his arch-nemesis, Professor Zoom, the Reverse Flash, assaulting the police officers. After taking out the gunmen, the Flash races after Professor Zoom.
The Flash gets his hands on Professor Zoom, only to have his old foe seemingly split in half, before counter-attacking. The Flash quickly recovers, then continues the chase. The two super speedsters circle the globe multiple times, with Professor Zoom effortlessly staying ahead of the Flash. In the Sahara Desert, the Flash collapses from exhaustion. Professor Zoom is quick to place a pair of heavy matter boots on the Flash's feet. The Flash begins sinking beneath the sand. As the Flash rapidly sinks from view, Professor Zoom taunts the Flash. Having come from the future, Professor Zoom knows the identity of the Flash's wife's murderer. A secret he refuses to give up, in the final moments before the Flash sinks beneath the surface.