Three act tragedy - Agatha Christie (Hercule Poirot #11)

Sir Charles Cartwright, the distinguished actor, had invited the local vicar and his wife to a house-warming party at his new country cottage. The Reverend Stephen Babbington, unaccustomed as he was to strong liquor, nervously sipped his cocktail, with a slightly wry expression on his face. The other guests continued to chatter. Suddenly Mr. Babbington's hand clutched at his throat, and, in a moment, he collapsed.

This was only the first act in the drama—a three-act tragedy with a mysterious death in every act. It is Hercule Poirot, the indomitable Belgian detective, who moves behind the scenes of this play and who finally rings down the curtain.