Airing July 3, 2011 on PBS Check local listings
"I saw a murder once...I did! I did!" boasts a clumsy, disliked girl at a Halloween party. For this, she is ridiculed and dismissed. But before the party's end, she is dead, snuffed out in an apple-bobbing tub. Party guest Ariadne Oliver — never again to consume another apple — summons her old friend Hercule Poirot for help and the gallant sleuth is only too happy to oblige. With the dubious help of the grisly old village witch and the wildly speculative mystery writer Oliver, Poirot must investigate old sins and discover the connections between a years-old stabbing, a Russian au pair, and a forgery to unmask a dangerous killer, all before another corpse surfaces. Adapted by Mark Gatiss (Sherlock) and based on the novel by Agatha Christie, Hallowe'en Party stars David Suchet as Hercule Poirot, Zoë Wanamaker as Ariadne Oliver, and Deborah Findlay (Cranford).