On his summer vacation, Galileo Galilei hears about the newly invented telescope and decides to build one of his own. Turning his new "spyglass" to the night sky, he sees things that no one has ever seen before. He discovers that the Milky Way is made of stars, and that the moon has mountains. He also notices a strange formation of "stars" that will eventually turn people's understanding of the world upside down. Fictional journal accounts capture the famous Italian scientist's curiosity and wonder as he makes some of the most amazing discoveries in history.