fall, he influences her to change her will to favour Miss Lawson, and later advises her companion to share out her inheritance to the Arundell family after the court case. Charles Arundell is a motor-boat racer and a friend of Captain Hastings, who attempts to beat the water speed record, and uses his aunt to finance the attempts. His sister Theresa is changed from the vain, young, engaged woman in the novel to a single woman in her late thirties. Bella Tanios does not leave on her own with the children, but is helped by Poirot and Hastings to the home of Emily's friends the Tripp sisters. No arsenic is stolen in the adaptation. The role of the dog, Bob, the dumb witness who is suspected of causing Emily's fall, is slightly altered in the television adaptation – in the novel the dog often left the ball on the landing, and the people of the house put it away, but on the night of Emily's fall the dog had been outside all night with the ball in a drawer. In the adaptation, the dog always takes the ball with him to his basket, never leaving it anywhere else, proving that when it was found on the stairs, it could not have been the dog's doing but must involve someone else; Bob was not outside the house when Emily fell in this adaptation. An additional murder was added into the adaptation – that of Dr Grainger. Whilst talking to Miss Lawson about Emily's death, he had suddenly realised the significance of the mist coming out of Emily as a sign, realising how she was poisoned with elemental phosphorus, but foolishly alerted Bella to his suspicions. Thus, Bella went to his room while he slept, and opened up an unlit gas heater, flooding the room with coal gas, killing him as a result. When Poirot reveals his findings to all, Bella does not commit suicide; she is present with the others, and exposed as the murderer, rather than being given a summary of it by Poirot on her own. Bob the dog does not return to London with Poirot and Hastings but is taken in by the Tripp sisters. The cast includes: Hugh Fraser as Hastings Ann Morrish as Emily Arundel Patrick Ryecart as Charles Arundel Kate Buffery as Theresa Arundel Paul Herzberg as Jacob Tanios Julia St. John as Bella Tanios