People Can Fly, the studio behind Bulletstorm and Outriders, has formally signed a work-for-hire agreement with Microsoft to develop a new project based on one of the Xbox maker's IP.
The announcement come via a statement posted to Polish financial site Interia Biznes, in which People Can Fly notes the game, which has been given the codename Project Maverick, will be fully funded by Microsoft with a budget of $30m-50m.
As to what the mystery project could be, the most obvious guess would be some form of new entry in the Gears of War series given the studio's previous connections with the franchise - it co-developed Gears of War: Judgment alongside its previous owner Epic Games in 2013, and was responsible for the Windows port of the original Gears of War prior to that.