Space can be lonely, so Moon likes to watch people down on Earth. There's just one problem: when Sun is out, everybody on Earth is happy to see him, but when Moon is out, everyone goes to sleep. This makes Moon upset. What Moon doesn't know is that little Lucy cares about her very much. Every night Lucy watches Moon from her bedroom window before she goes to sleep. But one clear night Moon goes missing. Can Lucy find Moon and will Moon learn just how much everybody actually loves her?