Dumb Witness

The renowned detective Hercule Poirot receives a letter from a potential client, Miss Arundell. The wealthy lady suspects her relatives of attempting to kill her, as she recently recovered from a fall down the stairs. The victim's nephews claim that the dog was to blame, as it had allegedly left its toy on the stairs, which caused Miss Arundell to trip. However, the case suddenly becomes more complicated: Poirot learns that the letter arrived after the lady's death.
The detective takes on a secret investigation of the probable murder. All of the woman's relatives have a motive, as her wealth should be inherited by them. When it becomes clear that Miss Arundell has rewritten the will, the mysterious deaths resume. Is one of the heirs trying to get rid of the competitors? Or are these deaths accidental? Hercule Poirot carefully collects evidence to eventually uncover the true cause of the murders.