Arlo is a house cat whose favorite activities are eating and sleeping. For the first two years of his life, he’s been living in a city apartment, his most ambitious goal to sun himself on a windowsill. When his human family moves to a distant suburb, Arlo spies a mysterious creature, unlike anything he’s ever seen, lurking just outside twelve-year-old Michelle’s bedroom window. His curiosity getting the better of him, Arlo’s investigation of the mysterious creature inadvertently puts Michelle in grave danger. Now, Arlo must work together with strange cats and one unusual human to save Michelle, no matter what the cost.