The story begins when Jane Wilkinson, a famous actress, asks Hercule Poirot to investigate the potential murder of her husband, Lord Edgware, a nobleman who was found dead in his study. Jane claims that she had been trying to get a divorce from her husband for years, as he had refused to grant her one. Jane insists that she didn’t commit the murder but had been out at a dinner party on the night Lord Edgware was killed.

Poirot’s suspicions are aroused because Jane seems to have an airtight alibi, and the situation is further complicated by the fact that Lord Edgware’s death looks like a staged murder.