While reluctantly attending a Vikings football game with his father, fourteen-year-old Zack Gilman finds himself transported to ninth-century Scandinavia amongst Vikings that look like people he knows and who see him as the fulfillment of a prophecy that will help them solve the riddle of Yggdrasil's chest.While attending a Vikings football game with his father, Zack finds himself transported to ninth-century Scandinavia amongst Vikings who see him as the fulfillment of a prophecy that will help them solve the riddle of Yggdrasil's chest.