Aston (Robert Shaw), a quiet, reserved man, lives alone in a top-floor cluttered room of a small abandoned house in a poor London district. He befriends and takes in Mac Davies (Donald Pleasence), an old derelict who has been fired from a menial job in a café. In time Aston offers him a job as caretaker of the house. Aston's brother, Mick (Alan Bates) - a taunting, quasi-sadist - harasses the derelict when his brother is away, countermanding his orders. Eventually Aston, himself irritated by the cantankerous old man, puts him out.
A struggling romantic accepts her aunt's wager: go on 40 dates in 40 nights to find true love. If she fails, her aunt will cover her rent and student debt. But the journey proves more challenging than expected.