Every thousand years, the gods of the world—from Greek to Norse to Hindu mythology—convene to decide whether or not to exterminate humanity. The council unanimously decides to exterminate all humans in response to their greed. Brunhilde, one of the 13 Valkyries of Valhalla, interrupts the gathering before the edict is implemented in order to offer mankind a shot at survival.
Brunhilde suggests staging Ragnarok, a contest in which the top 13 mortal warriors square off against the top 13 gods in single combat. Even though the gods mock the trial, the demigod exploits their conceit to coerce them into making a concession. But before they meet an untimely end, Brunhilde herself must assemble the greatest warriors in all of human history and lead them to triumph.