The wizards of Unseen University are again called upon to defend their creation, Roundworld, this time in a courtroom where its very existence hangs in the balance. The Omnians fervently believe that the world is round, not flat, and view the discovery of Roundworld as a vindication of their faith. To leave this artifact in the hands of the wizards would be unacceptable. Not only do the academics hold that Discworld is flat, but by creating the Roundworld universe, they have elevated themselves to the level of gods. Ankh-Morporks venerable tyrant Lord Vetinari agrees to a tribunal, where the wizards Ridcully, Rincewind, and Ponder Stibbons can present their casewith key assistance from a Roundworld librarian named Marjorie Daw.