Based on the novel by Agatha Christie, a posh 1937 tour of the holy land turns murderous when a malicious, malevolent matriarch (Piper Laurie) is mysteriously poisoned. Each of her fellow tourists had the means and the motive to kill her and any of them would have enjoyed plunging the lethal hypodermic syringe into Mrs. Boynton's fleshy arm. It's up to nimble-witted Belgian detective Poirot (Peter Ustinov) to discover whodunit.