The Assassin's Creed series' creative lead, Patrice Désilets has quit Ubisoft, the company's confirmed.
Désilets has been the creative force behind both Assassin's Creed games and the excellent Prince of Persia: Sands of Time.
A publisher spokesperson said: "With his role on project essentially done, Patrice Désilets has decided to take a creative break from the industry and is no longer working on Assassin's Creed Brotherhood."
The Désilets departure is a huge blow to Ubisoft Montreal, which recently lost Splinter Cell mastermind Clint Hocking and famed producer Jade Raymond, who left to assume control of the new Ubisoft Toronto studio.
The news arrives ahead of Ubisoft's Assassin's Creed: Brotherhood unveiling, due to happen at its E3 press conference early tomorrow morning (BST).