Katja and Andreas, a young couple, have rented a run-down old flat in Vienna. On moving in, they discover a mysterious chest left by the previous tenant – the old circus prop awakens their curiosity and inner fears. During the first night in the flat Katjas fears become true: something inside the flat is wrong – the front door is open. After her boyfriend mysteriously vanishes, Katja is on her own. What mysterious scheme is going on? Soon Katja finds out what is inside that sinister chest – and becomes another victim of Vadim, who still seems to be a part of the flat.