Checklist for Chapter 11 (In the Depths). Flooded RAS · music instrument · UZ-9.
| Goal | What to do | Codes / Collectibles | Status |
|---|---|---|---|
| Flooded sectors | Emergency controls A–E · optional vent secret room tablet | He Walks Behind the Wall | Attributed |
| Music puzzle | Nine-note instrument | Code 1-2-4-6-4-5-3-7-2 · Puzzle page | Attributed |
| UZ-9 optional | Crane machine · iron coins | Adult Toy | Attributed |
| Terminals / projector | Elevator sector · conference hall | T06–T07 | Attributed |
Ch10 · All chapters · Ch12