Originally known only as the "Forerunner Trilogy," the series was officially announced at the Emerald City ComiCon in Seattle, Washington, where its author, Greg Bear, made a guest appearance. The first book's working title was "Antediluvian." The word "antediluvian" means: "of or belonging to the period before a flood," hinting that the novel takes place prior to the Forerunner-Flood war. The series reveals a great deal of new information about the Forerunner-human interactions in ancient history. On October 11, 2010, the official name of the book was revealed to be Halo: Cryptum.