History: (Action Comics #21)-Terry Curtis was a brilliant scientist who secretly split the atom in mid-1939. He was kidnapped by the Ultra-Humanite and forced to participate in Ultra’s attempt to blackmail Metropolis. Terry turned against Ultra-Humanite, and helped foil this plan.

Terry continued his atomic experiments, but also took time to start a family, marrying and having a daughter. In late 1941 one of his experiments went haywire, killing his wife and fatally irradiating both Terry and his infant daughter Terri. A few days later Terry was contacted by the Ultra-Humanite, who offered to use his futuristic machinery to save both Curtises in exchange for Terry’s servitude. Terry agreed, but the Ultra-Humanite didn’t truly keep his word. Terri’s condition was only stabilized and Terry’s body structure was altered so that it was now powered by the radiation, granting him super-powers. Terry was dubbed Cyclotron and sent on a mission to steal a mystic object known as the Hammer of Thor. During the robbery he came into conflict with the All-Star Squadron and fled. While escaping Cyclotron accidentally killed a policeman, and was consumed with guilt. In a later battle against the All-Star Squadron, Ultra-Humanite was poised to murder them, and Cyclotron could take no more. He grabbed Ultra-Humanite, and flew into the stratosphere, where he allowed his atomic energy to detonate. Cyclotron perished, but Ultra-Humanite would survive and return to plague the world. All-Stars Firebrand II and Atom I adopted Terri and found a cure for her radiation poisoning. Terri would one day give birth to the superhero Nuklon.