In 1944 the Nazi military and scientific departments are researching the occult. Russian mystic Grigori Rasputin builds a dimensional portal off the coast of Scotland, where he intends to use it to bring about the destruction of Earth. In his employ is the ultra-silent assassin Karl Ruprecht Kroenen, who seemingly can't be killed. However, the United States has sent forces of their own to Scotland, along with Professor Trevor Bruttenholm, who is well-versed in terms of magic and sorcery. Fighting breaks out between the Nazi and American soldiers. When the device is damaged, Rasputin's life force is drawn through the portal and he disappears. Bruttenholm saves a mysterious red demon who is given the nickname "Hellboy." Sixty years later, FBI agent John Myers is sent from Quantico to a building in Newark, New Jersey which has been identified as Squeaky Clean Waste Management Services. Hellboy has to defend the city, while trying to protect his friends from each attack. He is eventually pushed over the edge when Rasputin has Kroenen kill Professor Bruttenholm