Postman Planet has a big secret.

Although he PRETENDS to be the best postman in the Universe, he's only nine. Anyway, he's on a mission to make an essential delivery to the Planet of Fluffy Unicorns: an inflatable planet that is, as we speak, deflating. It's upto Postman Planet and his ANNOYING new assistant Stamp, who is part-robot part-dog, to save the day!