In a bid to escape the incessant attentions of a man she does not love, governess Lucy Hayes embarks on a journey to begin a new post. But when she's stranded in a storm, her plans go shockingly awry. Desperate times call for desperate measures: against her better judgment, she agrees to a foolhardy scheme presented by a handsome stranger, known to her as only William. But when her mysterious benefactor falls ill, she finds herself unwittingly drawn into his family home in a case of mistaken identity: they believe she is William's betrothed. Though she realizes she should admit the truth, the family's warmth and welcome make it all too easy to play along, just for a while. Until she meets Baron Lord Simon Calloway, William's older brother.

Simon is suspicious of his lovely future sister-in-law, a woman who seems completely unsuited to his self-important brother. As they wait for William to awake, Simon and Lucy are drawn ever closer together. But danger draws closer too, in the form of her unwanted suitor. Lucy knows that when Simon discovers the truth, he will despise her. Now she must find a way to keep herself safe . . . and avoid falling hopelessly in love with a man she can never have.