Kid and his weapons are investigating the Black Dragon, who have terrorized the Baltic Sea recently. The investigation leads them to a ship called Nidhogg, and a evil soul controlling it. As they find the evil soul, he sends Liz to the deck below, where she has to face some strange companions, but she has to gather the mental strength to get back to Kid and help in the fight. However, that's only the beginning of their troubles, because soon, the real Black Dragon arrives.