Hyresgästen: The young architect Walter leaves his wife Linda to go to L.A. to draw a mansion for Harrison. On the highway a truck driver almost drives him off the road. Walter calls the truck-company to complain. The driver gets fired. When Walter arrives to the apartment-block where he has rented a flat he meets the choleric landlord William and the others living there. But now the problems starts. The next morning somebody has ruined his drawing and Harrison dislikes what Walter has drawn. But soon everything gets out of hand. Walter gets into more trouble - one morning he finds rats all over his apartment and the next day he finds his beautiful neighbor killed in his bed - and he starts to think that it is the fired truck driver who is out to get revenge.