It is 1957 and light pollution in London has led to astronomers from the Royal Observatory in Greenwich relocating to the English countryside. A completely new Observatory has been built and named after the local village, Herstmonceux. David Smith cannot concentrate any more in school and his imagination runs riot but there seems no way for him or his best friend Philip Teston to ever get to the telescopes. But two unexpected things happen. An Astronomer comes to stay at David's house and they meet Sonja, the daughter of a visiting Professor. The path is open to the Observatory, but they could never guess what they discover there will live with them for the rest of their lives.