Hellboy: The Science of Evil
The plot opens in Romania where Hellboy has been sent to track a crazed witch through an abandoned graveyard inhabited by werewolves and the undead. As he battles the witch, she shapeshifts into a swarm of crows that retreats and takes refuge in the nearby village. When Hellboy arrives, he's ambushed by a Nazi soldier and pushed downhill into the village.
The action shifts to 25 years earlier in an unknown part of rural Japan where Hellboy has been sent in to investigate reports of paranormal activity. He is quickly attacked by an Oni. It's revealed through an old monk later that the Oni's hostility is because their sacred artifact was stolen by the Nazis' under the command of Herman von Klempt who is seeking to use it for their own gain. After heading into the cliffs, Hellboy spots Klempt but is attacked by one of Herman’s Kriegaffe. Their fight continues in an old temple until Herman falls over the cliffs after accidentally being struck by a log thrown by his own minion. Hellboy returns the artifact to the old monk.
The story continues back in the present in Romania with Hellboy pursuing the witch into the abandoned village, which is filled with the undead and Nazi robots battling one another. In a final battle with the witch in the village church, Hellboy pulls down the giant bell, crushing the witch. This is followed by the collapse of the church itself with Hellboy falling into the underground catacombs, where he finds a group of excavating creatures resembling an Ogdru Hem, also swarming with "frog monsters". Eventually Hellboy destroys the foundations of the catacombs, causing it to cave in and knocking him into an abyss.
The following chapter again follows Hellboy on a past mission 40 years ago in the Tunisian desert. He stumbles upon a wounded alien soldier who tells of the Nazis yet again attempting to gain power. This time they tried to use an alien beast, but failed and even though the alien is contained in a crystal prison, it was controlling the fallen Nazis in an attempt to destroy all life on Earth. Further on another soldier reveals that the beast had followed the alien soldiers to Earth. Hellboy then tracks down and battles the giant worm while underground. Eventually he leads the worm to the surface and defeats it.
Back in the present day, Hellboy wakes up after washing up on the shores of an unknown part of Eastern Europe. There he finds a giant castle on the cliffside. He tries to send a transmission for backup, but his radio signal overlaps with Herman von Klempt’s, alerting each to the other's presence. After making his way further into the castle, Hellboy encounters an undead soldier who tells him the castle was built by the Nazis to carry out their experiments, with Klempt returning to finish his work. Hellboy eventually tracks down Klempt to his laboratory. Klempt releases a giant cyborg mutant to kill Hellboy, but during the battle Klempt’s control room catches fire and he is badly burned revealing him to be a robot. After Hellboy and the cyborg continues their battle outside, Klempt's real head appears in a hovering jar. Hellboy grabs Klempt's jar and forces it into the power core on the mutant’s back, causing it to explode, throwing Hellboy off the castle and into the ocean. After emerging from the water, Hellboy watches the castle's destruction only to suddenly spot the same swarm of crows the witch turned into leading Hellboy off once again on another mission.
good versus evil, violence, humor