SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!
SPOILERS AHEAD
Room 203 Plot Summary and Synopsis
When best friends Kim and Izzy move into a dark and mysterious apartment known as Room 203, they become convinced their new home is haunted by evil spirits. As they investigate the tortured history, they unearth a terrifying past of disappearances, demonic rituals and possessions that plagued every former tenant of Room 203.
Source: Wikipedia (CC BY-SA 3.0).