A criminal from the dimension of Korakar Lok intends to permanently steal Flash's speed.
Police forensics scientist Barry Allen, receives word that his girlfriend, Picture News reporter Iris West, is interviewing the Flash. Allen changes into his Flash costume to confront the imposter. Allen has difficulty getting into costume, then knocks himself out, running into the wall. Dazed and sprawled on the floor, the Flash realizes he's lost his super-speed powers. The Flash decides to confront the imposter anyway, as Allen. Arriving at the offices of Picture News, Allen is introduced to the Flash by West. At West's request, the Flash completes three feats of super-speed. Allan is amazed to discover that this Flash's super-speed surpasses his own.
Back at police headquarters, Allen finds a mysterious woman waiting for him. It is Doralla Kon, an extra-dimensional alien from the planet Alkomar, a world where everyone possesses super-speed. It is Kon who has stolen Allen's super-speed. The man masquerading as the Flash is a criminal scientist from Alkomar, Korakar Lok. Using a device, called a Celeri-Nuller, Lok transferred the super-speed powers of Alkomar's entire populace into himself. The process, though, proved too much for Lok's muscles. Traveling to Earth, Lok took on the Flash's mantle to lure the real Flash to him. Lok intended to steal the Flash's super-speed to provide a stabilizer for the power he drew from the Alkomaran populace.
By preemptively stealing the Flash's super-speed before he encountered Lok, Kon has thwarted Lok. Kon convinces Allen to come back to Alkomar with her, to destroy Lok's Celeri-Nuller. After Kon has returned his super-speed powers, Allen, as the Flash, storms Lok's stronghold. Lok's sentries are momentarily caught off guard by the Flash, believing him to be Lok. After a pitched combat, the Flash triumphs over Lok's three guards. Using an Alkomar weapon, the Flash destroys the Celeri-Nuller, returning the stolen super-speed powers to the planet's populace. The Flash returns to Earth, with Kon, and learns from West, that Lok has cut a path of destruction across the Earth.
Lok is desperate to draw out the Flash, so that he can steal his super-speed, with the portable celeri-nuller, hidden behind his chest insignia. The Flash races to California, to confront Lok. Vibrating his molecules into an intangible state, the Flash hides inside a tree, then strikes as Lok passes. With his first strike, the Flash destroys Lok's portable celeri-nuller. Though Lok still possess greater speed, the Flash's greater experience allows him to outmaneuver and, eventually, overcome Lok. Kon draws out the rest of Lok's super-speed, and returns him to Alkomar. The Flash hopes that the next time he encounter Kon will be under happier circumstances.
Looking to forcibly retire the Flash in his prime, the Top steals a vial of a rapid aging serum. The next day, the Top steals one of the Mirror Master's looking glass weapons, from an exhibit at the Flash Museum. The Top leaves behind a taunting note, daring the Flash to stop his crime spree. The Top strikes again, at the Flash Museum, but this time the Flash is on hand to stop him. Quickly the Top detonates the top grenade filled with the rapid aging serum. In a matter of seconds, the Flash grows extremely old. After belting the aged Flash into unconsciousness, the Top escapes.
The Flash, though, actually vibrated his molecules into an intangible state, allowing the rapid aging serum to pass harmlessly through him. With the theatrical help of the Flash Museum's curator, Dexter Myles, the Flash used old age make-up to fake the transformation. Still pretending to be extremely old, the Flash tries, and fails, to stop the Top's next robbery. On their next encounter, though, the Flash turns the tables on the Top. The Flash undergoes a bizarre rapid evolution, seemingly brought on by the spinning vibrations of the Top's weapons.
With his newly evolved psychic abilities, the Flash thwarts the Top's robbery. Using a holographic Top projector, the Top flees. The Top is just about to expose himself to the rapid aging serum, to then evolve as the Flash has, when the Flash snags the vial from him. After beating down the Top, and carrying him off to jail, the Flash relays the secrets of his "evolved" powers to Myles. The Flash Museum curator now has a new Flash tale to share with his patrons.