Ezio has always had a base of operations in the Assassin's Creed games—from his mansion in Monteriggioni to his lair in Rome. Revelations will continue this fine tradition, as Ezio is welcomed into the Assassin Brotherhood in Constantinople, who operate out of a den.
Ezio must defend the Assassin's den against waves of Templars with the assistance of his fellow Assassins in a new game mode called Den Defense. The mode uses Tower Defense mechanics not unlike that of Orcs Must Die! and Gears of War 3's Horde Mode.
As Ezio becomes more successful in repulsing the attacks of the Templars, he will gain the support of new units and structures to better defend the base.
Assassin's Creed Revelations is bound for release on the Xbox 360 and PlayStation 3 on November 15.