A trio of photographers spy a gorilla, walking upright, like a man, through the jungle. To their astonishment, the gorilla disappears before their very eyes. In reality, the gorilla, Jroyy, has merely passed through the barrier of invisibility surrounding the hidden Gorilla City. King Solovar presides over the execution of the Super-Gorilla, Grodd. In Blue Valley, Wally West narrowly avoids revealing his secret identity, as Kid Flash, to his mother. On a picnic with his girlfriend, Leslie, West allows his preoccupation with his private thoughts to cause him to neglect Leslie. West's Kid Flash costume is accidentally released from his ring, by an errant contact with Leslie's hand. Leslie, though, is too busy storming away to notice that West's dog, Lightning, is running off with the costume.
West retrieves his costume, before hearing the sound of his motorcycle engine revving up. Fearing that someone is trying to steal his motorcycle, West investigates, as Kid Flash. To his astonishment, he finds Leslie riding his motorcycle, as she barrels straight at him. Kid Flash dodges Leslie's charge, then pursues Leslie. To his amazement, Leslie is able to outpace him, by racing at super-human speed. Leslie evades Kid Flash's first attempt to grab her, then keeps him at bay, by pelting him with rocks, kicked up by the motorcycle. Suddenly, an electrical discharge from the motorcycle floors Kid Flash. Kid Flash regains his footing, and continues his pursuit. Just as he makes contact, Leslie is consumed, by the friction heat generated by her super-human velocity.
As the bike explodes, Kid Flash is thrown through a strange super-speed barrier. Kid Flash races back to find the real Leslie hitching a ride with a passing motorist. The Leslie he had been pursuing was merely an illusion, revealed to him when he briefly made contact, only to have his arms pass right through her. Unseen by Kid Flash, Jroyy lurks behind a tree, wielding an advanced weapon, seemingly satisfied by the recent events. Back at home, Kid Flash, as West, reveals his secret identity to his parents. The Flash arrives in Gorilla City. Speaking with King Solovar, the Flash learns the details surrounding Grodd's execution. Though King Solovar desired to imprison Grodd, the High Council of Gorilla City, led by Jroyy, voted for Grodd's execution.
King Solovar yielded to the will of the High Council. The Flash returns to Central City, taking time out to prevent a traffic collision, before reporting to work, as police forensics scientist, Barry Allen. The Turtle attempts to perfect a new weapon. The Turtle fails, but while he is distracted, Jroyy surreptitiously perfects the weapon. Allen is on the phone with his wife, Picture News reporter, Iris West Allen, discussing a wedding gift for Allen's laboratory assistant, Patty Spivot, when Allen hears a police bulletin regarding a robbery. Allen investigates, as the Flash. The Flash confronts the Turtle. Hit in the face by the Turtle's new "Slow Laser", the Flash finds his visual perception altered. Suddenly, everything seems to be moving at super-human speed around the Flash.
The effect is so disorienting that the Flash is incapable of stopping the Turtle from escaping. The Flash, as Allen, is rescued from the crime scene by his wife. On the ride home, Allen explains that his super-speed perception has been slowed down to the point that now everything seems to be moving at super-human speed. Vibrating his molecules into intangibility, Allen, as the Flash, circles the globe, moving faster and faster until he reaches hyper-light speed velocity. The Flash crashes through the same super-speed barrier Kid Flash passed through, in Blue Valley. Upon returning to Central City, the Flash's visual perception has been restored to it's normal parameters. After destroying the Turtle's base of operations, the Flash quickly defeats his old enemy.
Back home, the Flash, as Allen, finally settles on a wedding gift for Spivot. Having revealed his secret identity, as the Golden Age Flash, to the world, Jay Garrick holds a press conference. In attendance are Johnny Chambers, and his cameraman, Tubby Watts. Unbeknownst to Chambers, Jroyy is also at the press conference, and trains a weapon on Chambers. A powerful blast of water crashes though a laboratory wall. Garrick pursues the massive liquid projectile, as the Golden Age Flash. Chambers joins the pursuit, as Johnny Quick. The Golden Age Flash deflects the liquid missile, before it can strike an office building. Johnny Quick moves in to assist, but actually makes the problem worse, purposefully, by splitting the liquid missile into three projectiles.
The Golden Age Flash traps the first projectile in his slipstream. The second projectile evaporates harmlessly. The Golden Age Flash vibrates his helmet, heating it up at super-human speed. Throwing the helmet into the third projectile, instantly converts the liquid into steam. The Golden Age Flash then draws the first projectile into a lake. Johnny Quick, as Chambers, discusses his incredulous actions with Watts. While Chambers is at a loss to explain his errant behavior, Watts noticed that Chambers misspoke the mathematic equation that transforms him into Johnny Quick, adding another variable to the formula. The Golden Age Flash, as Jay Garrick, is getting a rubdown from his wife, Joan, when Chambers arrives at his door.
Chambers reveals his secret identity to the Garricks, then proceeds to kidnap Joan, as Johnny Quick. Garrick tears after Johnny Quick, as the Golden Age Flash. Johnny Quick releases Joan, then attacks the Golden Age Flash. The two speedsters race around each other, attempting to suffocate one another with a super-speed generated vacuum. Suddenly, the Golden Age Flash breaks through the same super-speed barrier, generating a shockwave that floors Johnny Quick. Upon recovery, Johnny Quick finds he is, once again, able to recite his transformative equation correctly. Allen, and West, are simultaneously compelled to put on their respective costumes, and run.
Upon reaching their destination, they are joined by the Golden Age Flash, who has been compelled to race through the dimensional barrier, between Earths 1 and 2, to unite with his fellow Flashes. It is then that they are confronted by Jroyy. The Golden Age Flash and Kid Flash quickly take down Jroyy, mistaking him for the Super-Gorilla, Grodd. Astonishingly, the Golden Age Flash finds that Jroyy is dead. Kid Flash is possessed by Grodd, who takes credit for killing Jroyy. Grodd's mind leaps from Kid Flash into the Golden Age Flash. As it turns out, Grodd was not executed, but rather had his molecules dispersed into another dimension, one only the power of super-speed could penetrate.
Taking possession of Jroyy, Grodd engineered three crises, forcing the Scarlet Speedsters into moving fast enough to weaken the dimensional barrier, allowing Grodd to return. With Grodd back on Earth, the Scarlet Speedsters go on the offensive. Having drawn himself back into the world through the power of the the three Flashes, Grodd finds himself, temporarily, endowed with super-human speed. A pitched battle ensues, with Grodd proving to be more than a match for the three Flashes. By merging his molecular structure with that of Kid Flash and the Golden Age Flash, the Flash is able to, finally, beat Grodd into unconsciousness. Grodd is brought back to Gorilla City for imprisonment.
Kid Flash, as West, graduates from High School. West's graduation celebration is attended by his friends in the Teen Titans, his family, the curator of the Flash Museum, Dexter Myles, Stacey Conwell, Sue Dibny, as well as Superman, Batman, and the Elongated Man, in their civilian identities. The next morning, West reveals to Allen his intention to retire his Kid Flash identity, in four years, after completing college.
Two text pages running down the many foes of the Scarlet Speedster.