'Rocks' Owen, the well-off owner of a car-hire business, is found murdered; the last place he was seen alive was the Blue Parrot nightclub. Scotland Yard go in to investigate, with the help of a visiting American detective and a nightclub hostess who may not be all she appears to be.
Four people with very different backgrounds meet by chance at an English pub and gradually become carried away in a bout of thrill-seeking. When their spree gets out of hand, each person faces a moral choice with lasting consequences.
A London cabby finds a greyhound puppy in his cab, and gives it to his daughter. She raises it and trains it up at the race tracks; and in spite of crooked rival owners, the dog eventually wins the Greyhound Derby.