In the Dark Ages, the evil Blood Queen Vivian Nimue unleashes a plague on England until King Arthur stops her with the aid of Ganeida, a member of her coven. Arthur uses Excalibur to dismember Nimue, and hides her remains across England. In present day Tijuana, Mexico, paranormal investigator Hellboy reluctantly kills missing agent Esteban Ruiz, whose mission got him turned into a vampire. After hearing Ruiz's dying words that the end is coming, Hellboy is brought back to the B.P.R.D. in Colorado. He is assigned by B.P.R.D. leader Trevor Bruttenholm, his adoptive human father, to assist the Osiris Club in hunting three giants. The club's seer Lady Hatton reveals that Bruttenholm was meant to kill Hellboy when he first came into the world as a result of the Nazis' Project Ragnarok. Meanwhile, the boar-like fairy Gruagach is advised by the witch Baba Yaga to retrieve Nimue's limbs, so she may grant his wish for revenge against Hellboy.
