Annie Kate Hinkley has always dreamed of being a Pinkerton Agent. Only problem is, growing up with her grandma, she never learned to shoot, ride a horse, or fight. But she did learn to read. And she read everything she could get her hands on about Kate Warne, the first female Pinkerton Agent.

Bruno Thomas has been a Pinkerton Agent for over a year. He's the youngest detective in the company, but the biggest, strongest man in the state of Colorado. Built like a solid brick house, he left a life of bare-fisted boxing to join Archie Gordon's extension office in Denver, Colorado, and doesn't ever want to go back.

In order to solve a murder, he must accept an undercover assignment that puts him back in the boxing ring. He's also required to marry a spitfire, overzealous recruit who idolizes Kate Warne.

Can these two find a common ground in their differences in order to discover true love? Or will Annie Kate and Bruno run headlong to the judge for an annulment as soon as they solve this murder mystery?