A folklore scientist becomes possessed by the ancient Japanese demons of Lightning and Thunder. But when The Bureau of Paranormal Research &amp. Defense dispatches a team of agents to investigate, a samurai sword sends Hellboy to a supernatural measurement of mayhem that is feudal, monsters, and witches. While fishboy Abe Sapien and pyrokinetic Liz Sherman battle with one very pissed off dragon, a cranky and lost Hellboy must get his way home.