Molly: The True Story of the Amazing Dog Who Rescues Cats tells the heartwarming story of the man-and-dog team behind the United Kingdom Pet Detective Agency–how Colin, in need of a new lease on life, rescues Molly the dog, and how Molly in turn rescues many more beloved lost pets.

As a veteran of the Royal Navy and longtime police officer, Colin Butcher was no stranger to dangerous situations. But a career in uniform can wear anyone down, so, in 2003, Colin left the force to start his own private detective agency, specializing in helping reunite people with their missing pets. And yet, despite his hundreds of successes, there were still heartbreaking cases where Colin couldn’t find the missing on his own. He knew he needed a partner.

When Colin first met Molly, his friends doubted that she would be up for the job. Where Colin was battle-tested, Molly was young and inexperienced. She was willful, wayward, and stubborn. But Colin could tell that Molly was unusually charismatic and intelligent. He decided to take a risk and bring on Molly for training.

Yes, Molly is no ordinary deputy, but a black Cocker Spaniel, and this is no ordinary detective agency. Trained by the top canine behavioral experts at Medical Detection Dogs, Molly can find missing cats–who are uniquely skilled at eluding humans–by detecting a unique scent signature, and she has been wildly successful.

The work is not always easy. Molly has faced hardships ranging from a near-fatal snakebite to the challenge of winning over Colin’s girlfriend, Sarah. But through it all, Colin and Molly share an enduring love and affection. More than a working relationship, Molly is part of the family. Together, they are the Sherlock and Watson of missing pets.