Whicher is engaged by Sir Henry Coverley, who suspects his wife Jane of infidelity and his sleuthing leads to his talking to the Coverley groom Josh and his wife Ruth, the village post mistress. Eventually he seeks out Jane's lover Matthew Thorogood, who insists that he genuinely loves her. However he is nowhere to be seen when the divorce case comes to court and he is later found dead. Whicher is surprised to meet Emma Finch, who has a child by Matthew and who confides that they were going to get married. Emma's brother Linus, who disapproved of Matthew, is charged with his murder but swears his innocence. Whicher revisits the Coverleys and notes that Jane seems unmoved by the death of her lover whilst Ruth informs him that Sir Henry has been in correspondence with a mysterious woman. To save Linus Whicher must lay bare the truth behind the Coverleys' marriage.