Goes someway to explaining why wizards aren't allowed to have sex - it appears to be far too dangerous for the rest of the world. A sourcerer appears at the gates of the Unseen University and demands to be crowned archchancellor, as he's plainly the most powerful wizard. After a few protestors are, um, quietened down, the wizards attempt to comply - only the Archchancellor's hat has had other ideas and has managed to get itself stolen. It travels across the ocean by means of Rincewind (a failed wizard), his luggage and Conina (A hairdresser with troublesome genes) to find a head it can use. It does so, although it's not necesssarily a sane one...The descriptions of the luggage suffering the combined pangs of rejection and too much drink are a delight. But the world cannot cope with the resulting magical wars and it's left to Rincewind to attempt to save the world armed with nothing more than a half brick in a sock.