Apollo the bookling comes across an old picture of Stripey the flag, who had been left behind on the Moon a long time ago. Apollo feels sorry for his friend and wants to be reunited with Stripey. He then sets out on a journey through space, along with Robin, Rosie, and Ellie the dog. They all hope to bring Stripey back to Earth. Despite some unexpected events along the way and on the return journey, Stripey is rescued from his lonely spot on the Moon. Once back home, he soon becomes the centre of attraction as crowds of people gather to admire him.