The Aperture is a Forerunner relic mentioned numerous times in Covenant holy scriptures, though the most detailed accounts were considered apocryphal by the Prophets until recently, their authors deemed to have misunderstood the original meanings, or worse, declared as Heretics by the Covenant and their works burned to destroy the "heresies" they contained. It is ironic that in their haste to begin their Great Journey, it is to these heretical works that they turned to in the end.