Amy's Pendant

Amy, the only child of a poor family living in the bustling city of Dolphin Point, is given an amazing and potentially dangerous pendant as a present for her fourteenth birthday. She does not know how amazing or how potentially dangerous it is. If she did, she would cherish it even more. She is that kind of girl.
Through her investigations of the mysterious pendant, she uncovers an ancient mystery—the remnants of a vast alien commercial enterprise buried beneath surface of the planet. Unfortunately, the central computer for the complex is aware of her intrusion and it cannot let her escape with knowledge of its existence.