At the Rider's home, Rich Rider is discussing his Nova powers with his family. Rich agrees to answer all of their questions if they agree to go on a picnic with him. The Riders happily agree and decide to go to Rich's Aunt Ellen's summer house at Montauk Point in Long Island.

At the summer house, Rich demonstrates his power of flight by taking his brother, Robert, for a ride through the sky! After making his brother sick on the "Nova Roller Coaster Deluxe", Nova takes his each of his parents for much calmer flights over the ocean. Afterwards, his mother, Gloria Rider, tells her son that she's worried about the risks involved in being Nova. Rich tells her that he understands but they agree to discuss it at another time.

Meanwhile, at a New York hospital, Mike Burley is waiting for information on a homeless man he brought in earlier. In the hospital's X-ray lab, the homeless man is having routine x-rays taken. The doctors are astounded to see the man begin to glow due to the x-ray treatment! The man screams that his unwanted powers have returned and flees by melting a hole in the wall of the lab!

Outside the hospital, Mike Burley confronts the stranger and asks for the man's identity. The man's red electrical glow fades and he tells Mike that he was known as the Comet. Mike Burley states that the Comet disappeared in the 1950's but the stranger looks no older than thirty. The Comet tells his new friend that, in 1956, he was on a desolate road when a gaseous comet struck him. The comet's light gave him super-powers which he used to fight crime as the Comet. Mike asks the hero why he disappeared after becoming a famous crime-fighter. The Comet looks away and says he doesn't want to talk about it.

Later that night, Rich decides to go on patrol as Nova. As he rockets over the city, Diamondhead instructs his gang to throw a brick through a jewelry store's window. As the diamond-hard villain expected, Nova quickly knocks out the gang. Diamondhead uses the distraction to knock a large portion of a building down on top of Nova!

Diamonhead gloats that Nova is dead and no one on Earth can stop him! As he attempts to steal the store's diamonds, the police arrive and begin shooting at Diamondhead. The super-villain laughs and begins attacking the officers. From the rubble rises the only man capable of stopping Diamonhead's rampage; Nova! The two foes begin to battle each other with neither willing to give in! Diamondhead knocks Nova unconscious with a blast of electricity from the city's power cables followed by smashing a car into him.

Afterwards, Diamondhead explains how he escaped the mountain the Sphinx had thrown him into during their previous battle. The Army Corp of Engineers were building a new army base and their dynamite blasts knocked him free. After telling his story, Diamondhead leaves the unconscious Nova trapped under the vehicle.

The police rush to the fallen hero but stand aside when the Comet and Mike Burley arrive. The Comet uses his electron energy blasts to free Nova and revive the young hero. Nova tells Mike Burley that he's been hiding for nothing. The police decided not to press charges after his brother, Sam, told them Mike was being forced to work for Yellow Claw. Nova thanks the Comet for his help and the two heroes join forces to find Diamondhead.

Elsewhere, the mysterious cyborg who disrupted Yellow Claw's attempt to destroy Washington, DC moves forward with his plans. The mysterious man of metal takes control of Diamonhead's television and warns him of the heroes' approach. The electronic being has created a holographic image of Diamondhead and has used it to lead the heroes to the real villain. The cyborg wants Diamondhead to destroy the Comet and bring Nova to him. Diamondhead refuses, smashes the TV and vows to destroy both of the heroes!