Halo: Cryptum: Book One of the Forerunner Trilogy

Almost nothing is known for sure about this ancient race. Worshipped by the Covenant as gods, their engineering relics pepper the galaxy, and their connection to humanity remains unanswered. Devoted fans of both the books and games will finally get to delve deep into the era of these enigmatic beings, and discover for themselves the epic story behind one of the great mysteries of the 'Halo' universe: the complete disappearance of the Forerunners from existence.