In the city of Hobarton, dogs and cats live in separate neighborhoods, each with their own mayor, schools, and police departments. Dina is a tiny Pekingese dog, who works as a private detective in the upscale neighborhood of Jasmine Hills, and she is bored by her cases, all of which involve innocent misunderstandings. One day, she receives a visit from a wealthy cat, Oralie, who wants Dina to find her missing brother, Clinton.

So Dina enters the world of cats to solve this mystery. She gets strange looks along the way, but she also receives help from a friendly librarian, meets a young cat who wants to be her partner, and learns about a camera heist. Will she discover what happened to Clinton? Or will the cats run her out of their side of town?