The Doctor and Romana are enjoying a holiday in Paris, 1979, when they become aware of a fracture in time. During a visit to the Louvre to see da Vinci's Mona Lisa, the Doctor purloins from a stranger, Countess Scarlioni, a bracelet that is actually an alien scanner device.
He, Romana and a private detective named Duggan are then 'invited' to the chateau home of Count Scarlioni...
In this suburban black comedy, bachelor Colin runs into old school crush Denise. Colin sees this as a second chance and attempts to court Denise, however, she and her boyfriend have less romantic plans for Colin.