When his wife (Christine Belford) is poisoned by cyanide in her champagne at their anniversary party, her husband (Josef Sommer) is determined to find out who murdered her. When he throws a party inviting the exact same guests, this time it is he who is poisoned by cyanide in his champagne glass. Will their be a third victim? Based on the Agatha Christie novel and directed by Robert Michael Lewis. This isn't one of Christie's best novels and the film makers make the mistake of not only updating the story from the 1940s but relocating it from England to Los Angeles. They've also gussied it up with things like a murder attempt on water skis, something Christie never would have done. They've also cast Anthony Andrews as a journalist (a character not in the book) to romance Deborah Raffin as the recipient of the murdered woman's fortune when the Christie source material had no romantic angle. Renowned mystery writer Sue Grafton is credited among the script writers but the screenplay is petty flat. When will film makers realize Christie knew what she was doing and stop trying to update or modernize her work? With Nancy Marchand, Pamela Bellwood, Harry Morgan, David Huffman and June Chadwick.