The story centers around John Smith, a London cab driver with two wives, two lives and a very precisely planned schedule for juggling them both, with one wife at a home in Streatham and another nearby at a home in Wimbledon.

Trouble brews when Smith is mugged and ends up in hospital, where both of his addresses surface, causing both the Streatham and Wimbledon police to investigate the case. His careful schedule upset, Smith becomes hopelessly entangled in his attempts to explain himself to his two wives and two suspicious police officers, with help from his lazy layabout neighbour upstairs in Wimbledon.