At the end of World War II, the Nazis attempt to open a portal to a paranormal dimension in order to defeat the Allies, but are only able to summon a baby demon who is rescued by Allied forces and dubbed "Hellboy" (Ron Perlman). Sixty years later, Hellboy serves as an agent in the Bureau of Paranormal Research and Defense, where he, aided by Abe Sapien (Doug Jones), a merman with psychic powers, and Liz Sherman (Selma Blair), a woman with pyrokinesis, protects America against dark forces.