Psychotic flatmates, although the development of this was underdone. With a couple of red herrings such as police investigating a disturbance and one flatmate being presented as creepy, this went towards the crazy a bit abruptly and simplistically. The film worked better at the start with the creepy vibe and would have been better not to veer away.
Some good work by the cast in this film, but ultimately we as the audience can't really sympathise with any of the characters. There is some misdirection in the film, which is a good idea, but it leads to an unsatisfying conclusion.