Seven kids, Thor's hammer and a whole lot of Valkyries are the only things standing against the end of the world . . . When thirteen-year-olds Matt Thorsen and Fen and Laurie Brekke - modern descendents of Thor and Loki - discovered they were destined to take the places of the Norse gods in an epic battle against the apocalypse, they thought they knew how things would play out. Gather the other descendents, defeat a giant serpent and save the world. No problem, right? But their journey grinds to a halt when their friend Baldwin is poisoned. Matt, Fen and Laurie must travel to the murky Underworld to try and save him before they can continue with their quest to find Thor's hammer. Ahead lie colossal monsters and legendary battles . . . Will Matt and the other descendents do enough to become heroes in their own right? Authors K.L. Armstrong and M.A. Marr return to Blackwell in the epic sequel to Loki's Wolves with more explosive action, adventure and larger-than-life Norse legends.