Only one piece of the Trident of Eden remains. Isaiah, a rogue Templar agent, has discovered the faith prong and the fear prong of this powerful relic. Should he possess the devotion prong, there is little that can stop him. For the time being, Owen and his fellow teens have established an uneasy alliance across Assassin and Templar lines in order to stop Isaiah while they still can. Over a thousand years earlier, Styrbjorn the Strong, a Danish warrior, led the Jomsvikings against the Danish king, Harald Bluetooth. It is on those Viking battlefields that the secrets of the devotion prong lie. It is there that the fate of the world, the truth behind the teens' collective unconsciousness and their ancestral links to one another lie.