The Man Upstairs

Trying to escape his guilt after accidentally killing his fiancee's brother, Peter Watson (Attenborough) changes his name and takes a rooms in a delapidated boarding house. There, his mental health rapidly deteriorates, and his fellow lodgers call the police after his erratic behaviour causes concern. But when Watson begins brandishing a gun, and a police sergeant is injured, matters quicky come to a head. (official distributor synopsis)