My Radical Roommate (2017)

Max, Marius and Marie share a flat. When rent suddenly increases, they find themselves in need of a fourth flatmate. They manage to find one but the euphoria of success doesn't persist very long: a series of mysterious incidents raises alarming questions. Why does their new flatmate drink so little? Why is there suddenly a Koran lying around in their hallway? And what is their new flatmate tinkering with late at night?