Police forensics scientist, Barry Allen, inexplicably wakes up in the bedroom of his counterpart on Earth 2, the Golden Age Flash. Allen is at a loss to explain how he came to be in the Garricks' home. Worse, the Golden Age Flash seems to be missing. Allen dons the Golden Age Flash's costume, and accepts an award in his stead. The ceremony is interrupted, when Allen spies an old man, "Dalvan", about to be run down by a tractor trailer. Allen rescues "Dalvan", only to learn that "Dalvan" purposefully placed his own life in jeopardy, to get close enough to speak to Allen.
Furthermore,"Dalvan" knows that Allen is not the Golden Age Flash. Allen accompanies"Dalvan" to his home. There, "Dalvan" reveals the Golden Age Flash's whereabouts. By Occult means, "Dalvan" opens a portal into limbo, so that Allen can retrieve the Golden Age Flash. Incredibly, "Dalvan" also produces Allen's actual Flash costume, for him to don. Swiftly locating his counterpart, Allen, as the Silver Age Flash revives the Golden Age Flash. The Golden Age Flash reveals that he was drawn into limbo to retrieve a meteor. Failing to do so will result in the destruction of Earth-2.
Unbeknownst to the Golden Age Flash, he has actually been compelled to retrieve the meteor that bestowed immortality on his arch-enemy, Vandal Savage. After living for centuries, time has finally caught up with Vandal Savage. Without a second exposure to the meteor's radiation, he will die. The Scarlet Speedsters catch up with the meteor, and trap it in their slipstream. The meteor is hurled out of limbo, and back into reality. When the Scarlet Speedsters attempt to follow it, though, they slam headlong into an invisible barrier.
Unconscious, they drift silently through the void, until they are found by Tempus, the Guardian Of The Time Stream. Unfortunately for the Scarlet Speedsters, Tempus refuses to allow them to leave. The Scarlet Speedsters battle against Tempus for their freedom. Upon their triumph, Tempus allows them to depart. Racing through the time stream, the Scarlet Speedsters begin to rapidly age. Only by running backwards are they able to reverse their accelerated aging. After navigating their way past a whirlpool, and a waterfall, in time, the Scarlet Speedsters finally make their way back to Earth-2.
Along the way, they discover that they have both been duped by "Dalvan", who is revealed to be Vandal Savage. The Scarlet Speedsters find Vandal Savage anxiously awaiting the arrival of his meteor. To prevent the Scarlet Speedsters from interfering, Vandal Savage imprisons them beneath a steel-mesh net. Vandal Savage suddenly realizes that he is in peril, when the meteor fails to slow it's descent, crashing into him with explosive force. The Scarlet Speedsters are blown free by the force of the meteor impact. While the Golden Age Flash believes that Vandal Savage has, finally, met his end, the Silver Age Flash has doubts.
This story was originally published in Showcase #4 (September-October, 1956). A plot synopsis of this story can be found at the link.