Andi and her younger brother, Bruce, live in a strictly no-pets household and are fast running out of ways to keep their perpetually hungry dog, Friday, under wraps. When they accidentally stumble on an abandoned hotel that is already home to a couple of resourceful strays, Andi has an idea. She taps Bruce’s mechanical genius for turning everyday objects into mechanical marvels, and, with the help of their friends in the neighborhood, transform the down-and-out hotel into a magical dog paradise--not only for Friday, but for every stray they can find. But when the barking dogs make the neighbors and the suddenly out-of-work local dog catchers suspicious, Andi and Bruce have to use every invention at their disposal to prevent them from finding out “who let the dogs in.”