The Ventilation System puzzle sits on floor -1F of Devil’s Reef, tucked into a flooded room with a red control panel. You need it running to clear out the hazardous gas and keep moving toward Lorelei the Siren. The panel throws three dials, four vertical gauges, and one large lever at you, and the goal is simple even if the trial-and-error is not: get every gauge inside its green target zone.
Quick answer: Turn the right dial once, the middle dial once, and the left dial once, then pull the lever down and push it back up. Turn the middle dial once, the right dial once, pull the lever down, and push it up. Turn the left dial once, pull the lever down and push it up, then turn the left dial one final time to solve it.
Where to find the Ventilation System panel
The room is on the basement level of Devil’s Reef, marked -1F on the elevator readout. From the flooded corridor, head to the red control panel on the wall. Interacting with it opens the puzzle interface, which shows the lever on the left, the four vertical gauges in the middle, and the three dials along the bottom.
How the dials and lever work
Each of the three dials changes how the gauges move. The lever on the left applies your current dial settings and pushes the gauges up or down. The trick is that you set the dials first, then pull the lever to test the result, then reset the lever before your next adjustment. When all four gauges land in their green zones at the same time, the puzzle completes.
| Control | Function |
|---|---|
| A | Select |
| B | Back |
| X | Reset |
| Three dials | Adjust individual gauge levels |
| Large lever | Applies the current dial settings to the gauges |
Full solution sequence
Follow these steps in order. Each “rotate once” means a single turn of that dial, and each lever pull should be reset before you touch the dials again.
How to know it worked
When the four gauges all sit in their green zones, the ventilation fan spins up and the gas begins to clear. Calvin confirms it out loud with the line, “There. That should clear out the gas.” Once the fan is running, the room is safe to pass through and you can continue toward your objective.
Tip: If a gauge overshoots its green zone, use the reset control to clear your inputs and start the sequence again rather than trying to correct it mid-run. The order above only works from a clean starting state.
