Having discovered a primary Assassin server cluster during the Millennium Raids, Abstergo analysts were able to recover a key piece of information – the location of the Hidden Library of Ivan Vasilyevitch beneath Moscow's Bolshoi Theater. The Templars believed that generations of Brotherhood leaders, including Ezio Auditore da Firenze, left confidential records in the library. Accordingly, they devised a plan to infiltrate and recover any and all information within.
Daniel Cross, now formally a Templar operative, was given the task. In October of 2002, he found a way into the library below the theater. There, he cut down the Assassin on watch and recovered Ezio's Codex. The tome contained details of his interactions with Those Who Came Before as well as a mention of a man named "Desmond."