Dark Water (2012)

Daniel is a young and ambitious real estate agent with a view to becoming a partner in the company. Along with the boss' wife Marie, he dares to spend a secret and passionate weekend in a luxurious archipelago house which he is supposed to sell. Once there, both Daniel and Marie discover that they are not as alone as they thought. George, a Polish craftsman, has stayed behind to finish work on the house and prepare it for sale. Soon however, what should have been a passionate and intimate weekend develops into something far more unpleasant.