Desmond Miles is held captive in a secret laboratory where scientists use the Animus to explore memories buried within his genetic heritage. Through the lives of his ancestors, including Aquilus in ancient Rome and Accipiter among the Germanic peoples, he discovers the existence of a centuries-old conflict between the Assassins and the Templars. Behind their struggle lies the search for artifacts capable of influencing the fate of humanity. As past and present begin to echo one another, Desmond realizes that his own role goes far beyond that of a simple observer and that the choices of his ancestors may determine the outcome of a battle that is still continuing in his own time.