In Assassin's Creed Mirage, Basim Ibn Ishaq is the former street thief who becomes a Hidden One in ninth-century Baghdad.
Basim begins as a young thief in Anbar, near Baghdad, and is drawn into the Hidden Ones after meeting Roshan. His training leads him into the Order's investigation of the Order of the Ancients, an organization connected to the later Templar tradition.
Mirage is set primarily in Baghdad during the Islamic Golden Age, with the story taking place in the 9th century. The game emphasizes stealth, investigation, parkour, and targeted assassinations, echoing the structure of the earliest Assassin's Creed titles.
Basim first appeared as an important character in Assassin's Creed Valhalla. Mirage serves as his origin story and explains events before his role in that later game, so he should not be confused with Eivor, Valhalla's protagonist.