Following the Cavern path to the Purifying Crystal starts a scene that closes the Deep Stratum for this run; a chase, the last fight and the credits come straight after. Before you go on, read the six files of this chapter: in the Pit Laboratory, File: On This Realm and Its Laws, File: On Vessel Synthesis, File: Recently Written Report and File: On the Recreation and Manipulation of Memory; then File: Wearily Scrawled Note (Passageway) and File: Ritual Text (Cavern pedestal). The Typewriter: Pit Laboratory (optional) is the last save; restock there too.