Twenty-five years ago, the Helliwells, the Parkers and the Soppitts were married on the same day by the same parson. They gather at the Helliwell home to celebrate their silver wedding. The new chapel organist tells them that he recently met the parson who conducted the triple wedding ceremony - he was not authorised to do so. Pandemonium breaks out when these pillars of society believe they have been living in sin for 25 years.