The game is set in 2012, with player-controlled protagonist Desmond Miles escaping from Abstergo Industries with an employee, Lucy Stillman, after being forced to relive the genetic memories of ancestral assassin Altaïr ibn La-Ahad
through a machine known as the "Animus." After escaping from Abstergo,
Desmond enters a device identical to the Animus and relives the genetic
memories of ancestral nobleman Ezio Auditore da Firenze, who lived during the Renaissance period of the late fifteenth century in Italy.
The player controls Ezio, who becomes an Assassin after his father and
brothers are murdered by a traitor to the Auditore family.