Mourdin was a treasure hunter in Ultima IX, along with his friends Castro, Felix, and Thadious. He died while searching the dungeon Despise for the legendary Kiran Shield, with the Kiran Stones as the key.
Mourdin had actually managed to find the blue Kiran Stone and even hid it quite well. But then he had a really bad idea and drank from a poisoned fountain and died on the spot from it. The Avatar found his body, and following his instructions, also the blue stone.