The Guide is a mysterious figure from DisCity's past who served the Keylan expedition when it explored DisSea between N.F. 23 and N.F. 25. Their identity is unknown, but they appear to have been a child at the time. It is also unknown whether the guide began the journey as a member of the team, or was found by the expedition while already inside BR-000. Given that the DisSea was and is an uncharted "death zone", it is also unknown how they were able to serve as a guide for the expedition team. Whatever the case, the guide owned a distinctive earring which, almost a century later, came to be in the possession of the Chief after it was purchased on the black market by Faye. When the Chief's consciousness enters Nightmare Space, its inhabitants believe the Chief to be the Guide due to their recognition of this earring. The guide is pictured on the Pioneer crimebrand.
The guide was instrumental in helping the expedition escape from a temporal loop that had stalled their progress for years. They instructed the expedition to follow the light of the rising Phantom Moon in order to "reach the stars"; doing so lead them on a path toward the dead city of Maria and, ultimately, the Source.
Due to their apparent familiarity with the Black Ring, and that the Moon entity has also appeared in the form of the guide to communicate with the Chief, the original child guide may have been an incarnation of this being, or some other form of Apostle, Great Existence, or predecessor of the Underground. Due to their similar hair color and cosmic connection to the Chief, the guide may also be the original person whom the Shepherd Plan used as a basis for its clones (if indeed the Shepherd Plan was a cloning program), or a youthful version of the Underground Shepherd herself.
As Keylan was the only surviving member of the expedition, the guide's fate is unknown.