William Miles
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William M. is a member of the Assassin Order, who acted as a contact for the Assassin teams spread throughout the world. Based in the Assassin headquarters, he regularly kept the teams informed about the situation of the others.
For the Assassin team in Italy, he mainly relayed information through Shaun Hastings and requested him to forward it to the other members. He also had a conversation with Lucy Stillman about the condition of Desmond Miles, who had been suffering from the bleeding effect, in which he said that they had to keep going, as they needed the location of the Apple of Eden.
In the Da Vinci Dissapearance when Ezio accesses the first memory the world appears to slow down while you hear Leonardo talking for the first time. Shortly after you hear two voices claiming Desmond has unlocked a memory from Ezio. One of the voices call the other William.