Mordred's House is the residence of Mordred before he was arrested for breaking the laws of nature. He worked on some experiments, some of them advanced the technology of the Kingdom of Arturus and brought them power. Others, like the Mechanical Mouse and Merlin, were illegal. There is a man who you must give the coin which you find in the fountain. You can find an library slip that you use to get to the castle dungeon and a missing page from Mordred's Journal, which tells the coordinates to Pewter Moon.