Galileo’s discoveries, and the manner in which he presented them in his 1632 book Dialogue Concerning the Two Chief World Systems, hurled his fate into the judgements of the Roman Inquisition. The Dialogue represented much more than a book on Copernican heliocentrism, and the fate of the book in the midst of the Inquisition placed Galileo in a precarious position. With us to decipher the controversy is John Heilbron, author of The Ghost of Galileo in a Forgotten Painting from the English Civil War.