The Sinking City 2 Ventilation Puzzle Solution

What the ventilation puzzle is asking

Players search for this one as the fan puzzle or the air vent puzzle; in-game it is simply the ventilation device, and it is the fiddliest input in The Sinking City 2 for a specific reason: the buttons do not move one thing each. Every press shifts several arrows at once, so the puzzle is a small system of equations rather than three independent dials.

The target state is simple — each arrow pointing at the green bar behind it. The sequence below reaches that state from the default position the room starts in.

Step-by-step

1. Press button one twice.
2. Press button two four times.
3. Press button three twice.
4. Pull the lever. This commits the current arrangement and shifts the frame.
5. Press button one one more time. The last arrow drops onto its bar and the fans start.

Count out loud. Most failures here are a miscount on the four presses, not a wrong understanding of the puzzle.

If your arrows are already out of position

If you pressed buttons before reading this, you are not starting from the default state and the sequence above will not land. Two ways out:

• Use the lever as a reset. Cycling it returns the mechanism to a known frame, after which the sequence works as written.
• Reload the last save. The safe room autosave is close by, and this is Frogwares' own recommendation for anything in this game that appears stuck.

Then work in the order given: all of button one, then all of button two, then all of button three. Interleaving presses is what makes the state hard to reason about.

Why this puzzle exists where it does

The ventilation room sits between you and the part of the hotel the chapter actually wants you in. It is the second of the hotel's three locks, sandwiched between the Lorelei lock and the room 301 safe, and together they are why The Wake-Up Call takes most players longer than chapter 1 despite being smaller.

It is also the game's clearest example of a puzzle with no document behind it. There is no note to find — the answer is the mechanism's own logic, which is why a written sequence helps here more than it does anywhere else in The Sinking City 2.

If the fans still will not start

• You skipped the lever. The lever is a step, not an optional confirm.
• You pressed button one a third time before the lever. Order matters: two presses, then the other buttons, then the lever, then the final press.
• You are looking at the wrong indicator. Alignment is judged against the green bars, not the arrow colours.
• The room is dark. Raise gamma or bring the lamp up; the bar behind the arrow is genuinely hard to see at default brightness.
• You are at a different vent. The hotel has more than one air duct interaction; only the panelled device with three buttons and a lever is this puzzle.