Mariah was a young mage in Moonglow, eager for adventure. If the Stranger told her of the quest for Avatarhood, Mariah would clamor to join the hero in the undertaking. The Rune of Honesty could be found near to the spot where Mariah had placed her gold, although it is unknown if the mageling knew this at the time. Mariah became a scholar at the Lycaeum, eventually coming to join the Council of Wizards. When the Avatar met with her in Ultima VI, she had become something of an expert in archaic magical languages, and was able to assist the hero in translating the Book of Prophecies which had been taken from the gargoyle priest participating in the attempted ritual slaying of the hero. Before she could accomplish this, however, she needed the Avatar to bring her the other half of a Silver Tablet, which held the key to the decoding the language in which the tome was written.
Upon translating the book, Mariah revealed that the gargoyles had prophesied that an evil one would appear to rob them of their holy book and destroy their home world, and that this personage would be responsible for the destruction of their race unless sacrificed. Analyzing this, Mariah made the connection that this "False Prophet" coincided with the person of the Avatar, and sent the hero off in search of Sin'Vraal of the Drylands - hoping that the gargoyle could tell them more.