Earthlings are great pets! On planet Blorx, Zira finally gets her own earthie, Rolo. His life as a pet is easy, with treats, naps, and walks to the earthling park — but also goopy canned food and a litter box. When the fanatical robots of the Animal Control Force try to catch Rolo, he runs away and gets lost in the city, where he discovers clues about the mysterious origins of his kind, the mythical planet Earth. Zira and her grumpy older sister Riffa must find her poor lost pet before the earthling catchers take him away, but Rolo may have ambitions of his own.

This fast-paced adventure is cleverly comical and genuinely heartfelt. Together, Rolo, Zira, and Riffa face the challenges of growing up and growing apart in this upside-down world.