The Barry Allen Flash is doing magic tricks at a charity event. However, during one trick involving him vibrating his molecules so fast they're invisible, he disappears from the stage and reappears in another city. Turns out that this city is Keystone City, home to the Jay Garrick Flash, who was previously written off as being a comic-in-a-comic. Barry (after looking up Jay in a phone book) met with Jay Flash. He discovers that Jay retired the same year his comic in Barry's reality got canceled. Barry thinks that the comic's creator was unknowingly basing the comic on events in Earth-2 (Jay's reality). Meanwhile, the Thinker, the Fiddler and the Shade united to get revenges of their old nemesis, Jay Garrick. The Flashes split up: Jay takes on Shade, Barry takes on Thinker, but the evil guys escaped and figure out there are two Flashes and warn Fiddler. Fiddler uses his magic music to mind control the duo and have them commit crimes. However, as the villains get the loot, the Flashes capture them and reveal they had jewels in their ears to block the music and played along to fool them. Jay decides to come out of retirement and Barry goes home.
LegacyDue this comic's success, many of the DC's Golden Age characters were revived. Later, crossover between Earth One (Barry's reality) and Earth Two (Jay's reality) became a yearly theme in the Justice League of America comics and led to the Crisis on Infinite Earths.