When a Nazi mystical experiment goes awry in 1944, the target of a wizard’s spell, the child of Satan, Hellboy, is wrenched from his home, and adopted by the U.S. agents who intercept his arrival.

Raised as a force of good, Hellboy grows up to be a full-fledged demon in the form of a man, complete with fierce red skin, a tail, a giant armored glove, and two large circles where his horns should be (if they ever grow back, Hellboy is quick to break them off). Now, the adult Hellboy, an investigator of the paranormal, is sent on a mission that brings him back in touch with the evil genius that started it all... that Nazi wizard.

Accompanying him along the way are other agents, including Liz, a pyrokinetic woman Hellboy has feelings for, and Abe Sapien, a mysterious amphibian hominid...