London, 1887

When newly graduated medical doctor Charlotte Duvall receives word that her father has died, she immediately leaves America and returns home to see to her family's estate. Among her father's possessions is a box of her late mother's letters, which feels like a balm to Charlotte's grief-stricken heart. But the letters contain some inconsistencies that suggest there was more to her mother's death than Charlotte had been told. She turns to the one man she trusts more than anyone—her treasured friend and director of London's police force, John Ellis.

John Ellis has harbored feelings for Charlotte ever since he first met her. Tucked into his heart are thoughts of her sharp mind, quick wit, and remarkable beauty. Though he has not yet found the courage to share his feelings with the young doctor, he is eager to help her in her hour of need.

Investigating the details of a death was not how Charlotte imagined she would find love, but as she and John work to unravel a dark web of secrets and lies, she finds herself relying on him more and more—and opening her heart to him in the process.

As the danger draws ever closer, John vows to do everything in his power to protect Charlotte from harm. But he fears protecting her heart might come at the cost of breaking his own.