Episode #504 "Dial M For Dick"

 Mary invites the Solomons to accompany her to a murder mystery weekend. The victim of bad prawns, she takes to her bed, unaware that the oblivious Solomons have no idea that all of the events are being staged by actors. Dick, incensed by the callousness of the other guests in the face of murder, and thinking Mary's illness stems from poisoning, decides to wrest control of the investigation from the actor playing Inspector Macaffrey of Scotland Yard (Billy Connolly). Dick enlists his family's aid in solving the murder, Sally calls in Officer Don. Tommy's been picking on the obsequious butler, Eames, and fears that if he's the murderer, he may retaliate. Dick announces to the assembled company that Mary is the murderer, but realized his mistake when two of the "murdered" actors appear in the living room in street clothes. Too late, the truth dawns on the family -- it's all just a show. Moments later, Officer Don bursts in with a SWAT team and tear gas. Oops.