Later, Moreau learns that his father was not the Count de Gavrillac, but rather the old Marquis de Maynes, Gavrillac's friend; the man he almost killed is his half-brother.
His father was not the Count de Gavrillac, but rather the old Marquis de Maynes. The man is his half-brother. He almost killed The man. Moreau learns this. This is later. The old Marquis de Maynes is Gavrillac's friend.