From the cosmopolitan capital of Sothis, Throne of the Ruby Prince, to the timeless ruins of the deep desert, adventurers brave accursed tombs and risk the wrath of forgotten mummies in this mysterious land of pyramids and pharaohs. Learn about every corner of Osirion, the backdrop of the exciting Mummy's Mask Adventure Path, including dangers of the desert, mysteries of the richest ruins, deadly new creatures, and everything you need to run a campaign in this exotic realm.