The Widow by Carole Mortimer

Six Dukes, bound together by their friendship and loyalty to The Crown. When one of them is murdered, the five friends remaining are each given the task of investigating one of the five officers suspected of being responsible for the killing.

Lady Elizabeth Marshall’s year of mourning for her husband will soon come to an end, at which time she knows her father-in-law, the unpleasant Earl of Whitlow, will demand she leave the country and return to London Society.
With a young son in the nursery, the earl’s heir now that her husband is dead, Elizabeth knows she will have no choice but to do as the earl instructs. But before arrangements can be made for her to return to London, she is surprisingly given a reprieve by her father-in-law when the arrogant Duke of Bristol arrives at his neighbouring estate and shows an interest in spending time with her.

Elizabeth knows the wealthy and handsome duke cannot seriously be interested in her, but she is grateful for anything which will allow her to remain apart from the Society which never really accepted her as Martin’s wife and the future Countess of Whitlow.
Sterling Bishop, the Duke of Bristol, has little time for Society and welcomes seeking out his friend Lincoln’s murderer as sufficient reason to leave London before this year’s Season is fully over. His quarry should have been Lord Martin Marshall, but as that gentleman is now dead, his widow will have to be the one to provide the information he needs.
Cold, often impatient, and always ruthless and haughty, Bristol is shocked when he realizes he is deeply attracted to the lovely Lady Elizabeth Marshall.

Can he continue to remain detached in his mission when his attraction to the lady burns so hot it quickly rages out of his control?