John and Joyce are lovers, she is a thirty five year old widow and John has been courting her for some months. They had been looking forward to the holidays when her two boys will be with their grandmother for a week and the lovers will have the house to themselves. Unfortunately a friend is going through a messy divorce and Joyce unwisely offers her a couple of days respite - which turns into more. However John is working for builders who are renovating the town museum and the old dungeons - a favourite with tourists. They decide to take up residence there while the builders are on holiday. Coincidentally the leader of a gang planning a wages robbery has also spotted the availabilty of the dungeon as a refuge while the police scour the county after the robbery. It really is very unfortunate.