Lily Thornton, daughter of the Duke of Breckenridge, unwittingly finds herself a suspect in a rash of jewelry thefts. In order to clear her name, she teams up with her best friend Emily's brother, the handsome Colin Dymoke, to find the real thief. To make matters worse, Lily's scheming former fiancé keeps turning up and causing trouble while making Lily question her own self-worth. Thankfully, she has Colin by her side to help and protect her. As they work to solve the mystery, Lily fights her growing feelings for Colin, who is considered one of England's most eligible bachelors. Having been hurt in the past, she's reluctant to entrust her heart to someone again. Before long, the two of them are caught up in a web of intrique and deception. They need to clear Lily's name before she and her family are ruined and all hope for romance with Colin is lost.

For years, Michael Balcarris has loved Emily Dymoke from afar. However, because of his secret profession, he is unable to admit his feelings for her and show his true self. Instead, he must continue to present himself as a frivolous fop to both London society and the woman of his dreams. As a young girl, Emily had a private crush on Michael, who had been her brother Colin's handsome and dashing friend. Yet upon Michael's return to London after attending university, she is unable to abide his insufferable presence. To make matters worse, he insists on being everywhere she is—including her family's country home when they go on summer holiday. During their time in the countryside, however, Emily starts to see a new side of Michael. She also has to fight her growing attraction to him, leaving her to wonder how she could be falling in love with a man she can barely tolerate.