The granddaughter of late Greek-British business tycoon Aristide Leonides, Sophia Leonides, visits private investigator Charles Hayward in his office. Sophia wants Charles to investigate Aristide's death, for she believes he was murdered by a member of his sprawling and idiosyncratic family. Sophia notes that Aristide' regular insulin injection had been laced with eserine from his eye drops, causing a fatal heart attack.