Despite being beautiful and wealthy, Lady Susanna Macalister's marriage prospects are rather lacking. To avoid a life of spinsterhood, she decides a loveless marriage to the dull and unromantic Lord Riverton is better than none at all. But still, Susanna longs for true, passionate love, the kind she grew up hearing stories about.

Enjoying a quiet walk with her insipid suitor one afternoon, Susanna is nearly trampled by the handsome Earl of Westcott as he rides through Hyde Park. Driven by his own guilt and despair, the earl embraces this chance encounter as an opportunity for vengeance, for Lord Riverton is the very man whom Westcott suspects is responsible for the untimely death of his beloved sister. But is his mission of separating Susanna from Lord Riverton simply a desire to save another unsuspecting lady from his sister's fate, or something deeper?

As Susanna helps Lord Westcott investigate her future fiance, she realizes she might have found what she was looking for all along. Can the pair keep their budding romance a secret from everyone around them until the investigation is over? Or will the unsuspecting Lord Riverton win Susanna's hand in marriage before the truth comes out?