Engaged as tutor to the children of wealthy and ambitious merchant, Samuel Appleton, Robert Fairfax soon finds that his employer has other work of a more delicate nature for him to do. Appleton's beautiful daughter, Charlotte, has made a very good marriage to the rakish and aristocratic Lord Mortlock - yet all is not well with the match previously backed so keenly by Appleton. Urged to investigate discreetly, Fairfax finds evidence of gambling debts, love affairs - and intrigue. When Lord Mortlock is found murdered in his bed, Fairfax urgently needs to find the answers to all his questions and unmask an evil killer...