Hastings is invited by his friend Charles Arundell to be at hand when he tries to break a water speed record on a Berkshire country lake, but his boat's engine fails him. At a subsequent reception at the estate of Charles' well-to-do aunt, Poirot and the other guests witness her refusal to continue to underwrite Charles' expensive hobby, and he threatens her. Later, when she is almost killed in a freak accident involving her pet fox terrier Bob, she confides to Poirot that she suspects a family member of trying to kill her to gain part of her estate. The detective advises her to disinherit her grasping relatives and name a friend as beneficiary. Despite this precaution, she dies abruptly under questionable circumstances, but the local authorities refuse to authorize an autopsy. Suspecting foul play, Poirot looks to his wits as well as the Arundell dog, who remains a silent witness to murder.