Ten years after the death of Orion I, his son Jupiter is kidnapped from his home/prison at a base in the Dakota Black Hills by a lone Grendel in full black body armor. This Grendel is known to others as the paladin, and later adopts the name of Grendel-Prime. Orion's widow Laurel Kennedy, now regent, sends the empire's elite soldiers known as Red Devils after the renegade Grendel and his hostage, so begins Grendel quest to protect Jupiter until he comes of age.