A folklore professor becomes unwittingly possessed by the ancient Japanese demons of Thunder and Lightning. But when The Bureau of Paranormal Research & Defense dispatches a team of agents to investigate, a cursed samurai sword sends Hellboy to a supernatural dimension of ghosts, monsters, and feudal mayhem. Now while pyrokinetic Liz Sherman and fishboy Abe Sapien battle one very pissed-off dragon, a lost and cranky Hellboy must find his way home.