The rigged piano at the village theatricals
In Ngaio Marsh's 1939 novel, the parish spinster Idris Campanula takes over the piano overture at an amateur performance in a village hall after her rival, Eleanor Prentice, withdraws with a septic finger. When Idris presses the soft pedal during her opening piece, a revolver concealed inside the piano fires and kills her. Inspector Alleyn traces the device back to a jealous rivalry over the rector: Eleanor had set the trap and arranged her own absence so that her rival would be the one to trigger it.
