Colin Butcher, a retired police officer, single-handedly founded a private investigation agency to search for missing and stolen pets, but quickly realized that he needed a companion. Meet Molly, a charming cocker spaniel abandoned by her owner and, by chance, discovered by Colin on the website pet shelter. Smart and charming, she melted his heart, and from then on the two became inseparable. Colin's detective skills, coupled with Molly's intelligence, poise and keen sense of smell, make them a formidable team, solving crimes across the country. From searching for Pablo, a fluffy ginger cat who went missing in Devon, to unearthing a treasure trove of stolen jewels in a forest in north London, the duo experiences many exciting adventures, meeting many new friends along the way.