Lucy Haskell is returning home to Denver after four years living abroad in China. She's eager to see everything that has changed in her absence and to start the next chapter of her life. When her dear friend and traveling companion, Delphine Collins, goes missing, Lucy realizes she's in a unique position to help. She decides to apply to become a Pinkerton agent, offering her familiarity with the culture to help search for Delphine in Chinatown.

Jed Green isn't sure what he thinks about ladies joining the agency. From personal experience, Jed knows it's dangerous work, and he can't imagine putting a woman in such a tenuous situation. When he's asked to train a new female agent, he reluctantly agrees. But when he's asked to marry her for propriety's sake? That's another thing altogether – how utterly preposterous!

Before Jed and Lucy can concentrate on their case, they must discover if they can work together. However, resolving their surprising feelings for each other, so they can focus on their dangerous task, is another thing altogether.