With five children, a raven, and a pet turkey named King Tut, the Stanley house is full-to-bursting. But David desperately wants a dog—even though his dad has forbidden another pet. So when Blair begins sleepwalking and having dreams of an enormous dog that comes to the house every night, David assumes Blair just wants a dog too. But what if Blair’s Nightmare, as the kids quickly name the dog, isn’t only a dream? Is Nightmare the dog they’ve always wanted? And how can the kids keep him—without letting their parents know?