Twelve keys, one secret. Odin and his twelve sons guard the secret to prolonging human life. The secret, kept deep in a vault in Ragnorok, can only be revealed when humans stop intentionally killing one another. Twelve humans hold the keys to open the vault, but during centuries of complacency, Odin has lost track of the keyholders. Two keyholders now remain, and Odin awakens to their existence. Can Odin and his sons protect the last two keyholders, or will Loki, Odin's greatest rival, destroy everything Odin holds dear and seize control of Ragnorok?