Dumb Witness (1937) is an Agatha Christie mystery featuring Belgian detective Hercule Poirot. Wealthy spinster Miss Emily Arundell, believing her life is in danger, writes to Poirot requesting his help. By the time he arrives, she has died from apparent liver failure, and her will has mysteriously changed, leaving her fortune to her companion instead of her greedy relatives. Suspicious of murder, Poirot investigates her nieces, nephews, and household members, uncovering secrets, financial troubles, and hidden motives. The title refers to Bob, Miss Arundell's wire fox terrier—the only witness to the culprit's cunning scheme involving a luminous mark on the staircase.
