The Cauldwells are a wealthy mining family led by miserly, ailing patriarch Ralphfred. Scheming elder daughter Daphne is married to embittered wheelchair-bound Greg whilst younger sister Joan is a simple, trusting, childlike soul who nonetheless accidentally poisoned her brother Neil when they were children. Gold digger Lucy arrives to marry Ralphfred’s son Rolph, though Rolph is more interested sexually in Lipton, his valet, and Lucy is dismayed to find that Rolph lied about his father being at death’s door. Learning that her father has changed his will to leave everything to his nurse Maria, Daphne seduces hunky but dim gardener Simon into poisoning Ralphfred against her, getting Maria sacked. A new will is announced - but this leaves everything to Imperial College to keep Ralphfred alive in suspended animation. Daphne also gets a shock when Lucy unveils a portrait of her when she was a mental patient.