Five close friends, all of them married, share a loft to meet their mistresses. One day they find the body of a young woman in the loft. Since there are only five keys to the loft, the five men begin to suspect each other of murder.

Vincke and Verstuyft are the best detectives of the Antwerp police department. They are confronted with the murder on a leading executive and put all their effort to catch the murderer.

Five married guys secretly share a penthouse loft in the city where they can carry out hidden affairs. But the fantasy becomes a nightmare, when they discover the dead body of a woman in the loft one of the group must be involved.