Captain Boomerang and the Trickster close in on the fallen form of their nemesis, the Flash. Weapons at the ready, the Trickster discovers that the Flash is already dead. Moments prior, the Flash had received a mental image of Captain Boomerang and the Trickster's whereabouts. As the Flash closed in on them, the villains also received a mental image of the Flash's route.With a rope stretched taut between them, the Rogues tripped the Flash, causing him to violently skid to a stop, face down on the ground.
What the Rogues could not see was that the Flash was caught up in the slipstream of an object moving even faster than him. So fast is the object moving, that the Flash exceeds the speed of life, and breaks through the life barrier. The object turns out to be a kind of guardian, tasked with patrolling the outer edges of the life barrier. A horrific creature, known only as the "Devourer", is consuming it's way into the Flash's universe. The Sentry has carried the Flash into the life dimension, to aid in the struggle against the Devourer.
Back on earth, Captain Boomerang keeps the Trickster from unmasking the Flash's lifeless body. The two Rogues begin arguing over who is truly responsible for murdering the Flash. Their debate is interrupted by the Super-Gorilla, Grodd. It was Grodd who projected the mental images that brought about the Flash's confrontation with Captain Boomerang and the Trickster. Grodd had planned for the Rogues to do his dirty work for him. All the risks would be on them. Captain Boomerang and the Trickster attack Grodd.
The Rogues prove to be no match for the Super-Gorilla. The Flash perceives the Devourer in different fashions, first seeing it as an enormous rat, then a flame-thrower. A giant ram then a Tyrannosaur. Once the Flash finally hits upon the correct super-speed motions to defeat the Devourer, the creature takes on the appearance of the Flash's wife, Picture News reporter, Iris West. From the Flash's point of view, it seems as if he's killing his wife, but the Devourer's last ditch psychological tactic fails.
The Flash doesn't falter in his efforts to destroy the Devourer. The Sentry returns the Flash's astral self back to the mortal realm, where it is reunited with his body. The Flash revives just as Grodd is psychically forcing Captain Boomerang and the Trickster to turn their weapons on one another. Vibrating at super-human speed, the Flash drives Grodd into the ground, then mericilessly beats him into unconsciousness. Captain Boomerang and the Trickster surrender peacefully.
Wally West stumbles across a bank robbery in progress. West activates the hidden spring that releases his KId Flash costume from his ring. Instead of his costume, though, the ring releases anesthetic gas, that knocks West out. Upon recovery, West realizes that he accidentally swapped rings with his laboratory partner, George, when they were in the wash room. Wearing a spare costume, West, as Kid Flash, gets on George's trail. As George's ambition has always been to take down a big fish in the criminal underworld, George has arranged to meet with a syndicate leader.
George activates the gas projector in "his" ring, only to see Kid Flash's costume spring out. The criminals, believing George to be Kid Flash, level their guns at him. Kid Flash disarms the crooks, then beats them all into unconsciousness. To protect his secret identity, Kid Flash allows George to believe that the gas in his ring slowly seeped out, and that Kid Flash threw the other costume into the room as a distraction.
This story was originally published in The Flash #119 (March, 1961). A plot synopsis for this story can be found at the link.