Boot was once a toy robot, but it has come a long way since it was scrapped and woke back up with only two-and-a-half glitchy memories. When Boot catches sight of a robot pet it used to know – Mr Piggles – our hero and pals follow it to a beautiful green square in the city of skyscrapers. Here they find not just real nature, but also a haven for broken and rejected pets. They also meet the children who look after the pets, and for whom this green space is a sanctuary too. But Boot is distracted by its emotions, swinging from happy to sad – maybe Boot is broken?