The Masyaf keys and what they reveal — the Isu, the Pieces of Eden, the full scope of what the Assassin-Templar conflict is actually about beneath the historical surface. The more Ezio learns is the more the comfortable framework of the Creed as a fight for human freedom is complicated by the revelation that the freedom humans are fighting over is itself a design of a civilization they do not remember and cannot fully understand.

The less he wishes to know is the game's most honest emotional note: the cost of understanding is the loss of the certainty that made the understanding worth pursuing.