Hipparchus and his sister Sappho live on the island of Samos in Ancient Greece. They spend their spare time listening to the ideas of their friend the Stargazer. They are enchanted by his stories about the stars, the sun and the Earth. But Hipparchus and Sappho discover that not everyone agrees with the Stargazer’s ideas, and stories can be dangerous. They must find their friend and warn him before it is too late . . .