Which light room are you in?
For the platform room, redirect the mirrors as new receivers appear, have Leni hold the broken mirror, then interact with the central pedestal to descend. The nearby room with 2 mirrors instead opens a door; its solution is the first section below.
These rooms are near the end of Chapter 3, “Those Before Us,” after the vision, raft crossing, and slope into the structure. For the earlier ruins viewpoint, use the watchtower looking-glass guide.
Open the door in the first room
Interact with the room’s receptacle to start the mechanism. Rotate and flip the 2 mirrors until their beams reach the receivers on either side of the large door. Both sides need light.
Once the door opens, go through and activate the next pedestal. You are now in the larger platform room with several mirrors, including a broken one.
Follow the receivers as they appear
Use left and right from the entrance while looking into the platform room. Solve each stage before moving on: the next wall receiver appears only after the preceding stage is activated.
| Stage | Mirror route | What changes |
|---|---|---|
| Far wall | Far-left mirror → working mirror on the right → far-wall receiver | A receiver is exposed on the left wall |
| Left wall | Redirect the working right mirror → lower-left mirror → left-wall receiver | The next receiver appears on the right |
| Leni’s mirror | Approach the broken upper-right mirror so Leni holds it; aim the upper-left mirror at her mirror | The final receiver activates |
After the final receiver activates, return to the receptacle in the center and interact with it. The platform carries you down; use the large door ahead to continue.
If the platform will not move
- No new receiver on the wall: finish the preceding mirror route before changing to the next stage.
- The upper-right mirror cannot stay in position: go to it so Leni can hold it, then operate the upper-left mirror.
- The light sequence is complete but nothing moves: interact with the central receptacle. The last beam is not the final input.
- Only 2 mirrors and a sealed door are visible: you are still in the first room.
Sources and limits
The room order, receiver sequence, Leni interaction, and platform descent follow the Chapter 3 section of Richard Seagrave’s GameSpew walkthrough, published August 27, 2026. This guide is limited to that written route; it has not been independently reproduced in-game here.
“Lens” and “mirror” describe the reflectors in these rooms. The guide covers the door room and the following platform room, not all Chapter 3 puzzles. Return to puzzles by location.