The Mystery of Hunter's Lodge (S03E11)

Hastings is invited to a grouse shoot which goes disastrously wrong when Archie Havering swings his gun too far around. With everyone in low spirits, the party begins to break up. Later that evening, a mystery figure arrives at Hunter's Lodge and murders Roger Havering in his gun room. Having taken to his bed at the local hotel with a high temperature, Poirot shakes off his illness to find the cold blooded murderer. (iTunes)