Verena Steynton (Judy Parfitt) is holding a party for her daughter. All the aristocratic families of Strathcroy in the Scottish Highlands are attending, with all their guilty secrets... Lord Archie Balmerino (Edward Fox), a crippled war veteran and his long suffering wife will be there. Edmund Aird (Michael York), a wealthy entrepreneur and his beautiful American wife have been invited. And Pandora (Jacqueline Bisset), Archie's exotic and mysterious sister, who disappeared from the village twenty years ago, is returning, under a cloud of suspicion. Only Edmund and her brother know the secret of her flight from home. But the rumours are flying and the local families feel that Pandora's return can only bring bad luck. When a lifeless body is found in the loch, the tension rises. Why has Pandora come back after so long? What are her motives? And has her return already had deadly consequences?