The Quigleys and the Drysdales are caught in an eternal quadrangle. When Clive and Sonia discover that their respective partners are having an affair, they realize that they are reduced to being the other half of an unpleasant equation. Unwillingly, they join forces in an attempt to save their marriages.

• Roy Clarke

• John Duttine
• Lesley Manville
• Ian McNeice