Gail Manners, daughter of world famous scientist-explorer, Doctor Robert Manners, lies in a coma. Gail had been suffering headaches, brought on by premonitions. After predicting the collapse of a local discotheque, Gail collapsed. Kid Flash rushed Gail to the hospital. Kid Flash, as Wally West, waits for news on Gail's condition, at the hospital. Doctor Manners inquires as to Kid Flash's whereabouts. Doctor Manners has a theory regarding his daughter's coma, but needs Kid Flash's help to test said theory.
Though too late to prevent a car collision with a fuel truck, the Flash rescues both drivers before they can come to any harm. The Flash generates a powerful updraft to carry the flames away from the wreckage, then creates a vacuum to extinguish them. The Flash is just about to stamp out the pools of flaming oil, on the street, when Kid Flash beats him to it. The two converse at super-human speed, as Kid Flash brings the Flash up to date on the Manners situation.
Years ago, the Manners, along with the Flash, Kid Flash, and Picture News reporter, Iris West, had been on an expedition to South America. Inexplicably, the violent tremors of an earthquake hurled the expedition party back in time. Gail Manners psychic abilities began to manifest, shorty after returning to the present. Doctor Manners believes that by returning to the exact location of his previous expedition, as well as traveling back into the past, a solution to his daughter's coma can be found.
The Flash agrees to accompany Kid Flash. Upon reaching the South American coastline, the Flash uses his cosmic treadmill to transport their entire ship, and all it's crew, back into the prehistoric past. Almost immediately, the ship is attacked by an Alzadasaurus. While Kid Flash pummels the creature's head, the Flash kicks up a powerful undertow that pushes the creature back out to sea. Kid Flash is thrown into the seabed, when the dinosaur dives beneath the waves.
Noticing that Kid Flash is nowhere to be seen, the Flash dives back below the surface, and digs Kid Flash out of the mire. Back on board the ship, the group is relieved to see Gail come out of her coma. The Flash and Kid Flash do some scouting. During their travels through the primeval landscape, they bear witness to several species of dinosaurs, employing advanced problem solving techniques, to better their lives. When the two heroes pause to discuss the situation, they're ambushed by Gryk-5, a reptilian alien.
Gryk-5 attempts to vaporize the Scarlet Speedsters, but they merely vibrate their molecules into intangibility, and slip beneath the ground. Coming up behind Gryk-5, the Flash and Kid Flash spin him around at high velocity. Gryk-5 teleports out of the speedsters' grip. Searching in ever widening circles, the Scarlet Speedsters track Gryk-5 back to the aliens' base camp, hidden within a dormant volcano. Using their Remma device, the aliens are boosting the dinosaurs' natural evolutionary growth, so that they remain the dominant species of the Earth.
While the Flash distracts the aliens into attacking him, Kid Flash runs around the volcano, generating enough vibratory force to cause an eruption. The explosive release of magma destroys the Remma device. The aliens depart the Earth in failure. Gail speculates that the radiation, given off by the Remma device, endowed her with psychic abilities, while also being responsible for her coma. With the mystery solved, the Flash uses his cosmic treadmill to return everyone to the present.