This book turned out to be much deeper and much more moving than I expected. Both Stephen and Mercy have been deeply affected by their experiences in the Crimean War -- Mercy as a nurse and Stephen as a cavalry officer. When they meet again in England, Stephen has no memory of Mercy (or of anything that happened to him during the war), and Mercy has an infant who she claims is Stephen's son, the result of just one night of passion.
Mercy and Stephen do not immediately fall in love. Indeed, they aren't even very comfortable around one another at first. Stephen has no interest in being tied down, especially given his precarious mental state, and he doesn't know if he can bring himself marry her. Mercy doesn't truly expect marriage, and even if they did wed, she knows he will not be faithful. His pre-war reputation as one of London's greatest ladies' men is well known to her.
Nothing comes easily to this couple, and that's one of the things that makes their story so enjoyable and touching. As in the other two books of this series (about Stephen's brothers), Stephen's family members play important roles, and their duchess mother sometimes steals the show. I wish Heath had given her a book of her own.
I read these books out of order; each works well as a stand alone. But why not read the entire series? The Kindle versions are priced at only $2.99. A real bargain for such an outstanding author's work.