Jack of Hearts, real name Jack Hart, is the son of scientist Philip Hart (creator of "Zero Fluid") and an alien woman from the Contraxian race. As a young man Jack was doused in Zero Fluid and gained super powers but was not in total control of his powers. In an attempt to control his powers, Jack of Hearts built a containment suit that resembled the Jack of Hearts playing card. The lack of control became a recurring theme with Jack of Hearts, including his stint in the Avengers where he had to spend 14 hours a day in a containment room to prevent self-destruction. When his powers became uncontrollable he chose to leave Earth, exploding in space without harming any innocent bystanders.