Agatha Christie's Poirot: Four and Twenty Blackbirds

At a London restaurant where he often eats, Poirot notices that another regular customer has diverted from his usual meal. As old Anthony Gascoigne lies dying in Brighton, his estranged twin brother, Henry, falls to his death. A tragic accident, or murder? Poirot begins to see connections and decides the answer to the mystery lies in a blackberry pie.