Chapter 5 Coloured Mirror Puzzle Solution in A Plague Tale: Requiem

The mirror room in Chapter 5, Desolation It Wrought, is where a lot of runs through the second trial stall out. Sophia drops into a wide chamber with three coloured light sources, a scattering of blank steel reflectors, and a stone column in the middle carrying red, green, and blue dials. Land each colour on its matching dial and the column gives up the first of the three symbols you need back in the entrance hall.

Quick answer: Burn every patch of corruption away first, then send green straight across to the reflector opposite it, red across to the low reflector on the far right, and blue through a four-mirror chain down the left side — each one finishing on its matching dial on the central column.

How the coloured mirror room is set up

Three coloured emitters sit around the outside of the room. Green is on the right as you come in, red is on the left, and blue sits in the middle at the front. Everything else in the chamber is a plain reflector that passes a beam along without changing its colour.

Walk up to the column in the centre before touching anything. Three coloured dials are set into it, one on the right face, one on the back, and one on the left. Those are your three targets, and knowing which face each colour needs saves a lot of blind rotating later.

Note: if the reflectors get tangled and you lose track of what points where, restarting the section from the pause menu is faster than untangling it by hand.

Burn the corruption away before routing any beam

The black growth smothering parts of the room does two annoying things. It blocks reflectors you need to reach, and it hides at least one mirror entirely. Light destroys it, so treat every beam you control as a cleaning tool before you treat it as a puzzle piece.

Take hold of whichever beam you are standing at and sweep it slowly across the nearby growths. Keep the light on each patch until it burns off completely rather than clipping the edge of it.

Aiming prompt on screen while sweeping a light beam across the corruption in the mirror room — Aiming a beam to burn off the black growth. Image: Focus Entertainment

Repeat this at every reflector you take control of, not just the first one. A mirror at the back of the left path only appears once the growth in front of it is gone, and the blue chain cannot be finished without it.

Green beam solution

Green is the shortest chain in the room, so it is the cleanest place to start.

Go to the green emitter on the right side of the chamber and turn it so the beam runs straight ahead into the reflector sitting directly opposite, near the back wall.

Walk over to that back reflector, clear any growth around it, then rotate it until the green light lands on the green dial on the rear face of the central column.

Sophia aiming a beam at a glowing circular dial beside a pool of blue water in the ruin — A beam locking onto one of the circular dials on the central column. Image: Focus Entertainment

Red beam solution

Red crosses the room in one long hop, ending up on the same side you just finished the green chain.

Head to the red emitter on the left and swing it fully to the right, aiming at the reflector on the lower platform over on the far right of the chamber, close to the green setup.

Move to that reflector and turn it back towards the column so the red light settles on the red dial on the right-hand face. That is red finished in two moves.

Coloured beams being angled from a mounted reflector toward targets across the ruined chamber — Rotating a mounted reflector to line a coloured beam up with its target. Image: Focus Entertainment

Blue beam solution

Blue is the awkward one. It passes through four mirrors, and the third link only exists after you have burned the growth behind the rock on the left.

At the blue emitter in the middle of the room, turn the beam to the left so it hits the reflector tucked behind the large rock on the raised platform.

Climb up to that reflector and use the light to clear the tall column of growth behind and to the left of the rock. A low-set mirror is revealed underneath it. Point the blue light down onto it.

Sophia climbing towards a large mechanical wheel on a ruined stone platform inside the temple — Crossing the ruined platforms to reach the next reflector in the chain. Image: Focus Entertainment

Drop down to the low mirror and angle it up and to the right, towards the reflector sitting on the slightly higher ledge beside it.

Climb up to that last reflector and turn it in towards the column so the blue light lands on the blue dial. All three dials should now be lit.

Beam routing reference

Colour	Route	Ends on
Green	Emitter on the right, then the reflector directly opposite at the back	Green dial, rear face of the column
Red	Emitter on the left, then the low reflector on the far right platform	Red dial, right face of the column
Blue	Emitter in the middle, then the reflector behind the left rock, then the hidden low mirror, then the reflector on the ledge to its right	Blue dial, left face of the column

How to confirm the puzzle is solved

The moment the third dial takes its colour, the central column reacts and the stonework around it shifts, opening the way up and out of the chamber. A pedestal is exposed at the middle of the room.

Place the Sphere into that pedestal. The symbol is revealed and written into Sophia’s book automatically, which is your confirmation that the room is done. Carry it back to the entrance hall and slot it into the matching pedestal in front of its doorway.

Why a beam refuses to reach the column

Growth is still sitting in the beam’s path. Light does not pass through it, and a partially burned patch still blocks the line.
The hidden low mirror on the left has not been uncovered yet, which makes the blue chain impossible to complete.
A reflector you already used for one colour has been rotated again for another, breaking the earlier link. Work one colour through to its dial before starting the next.
The beam is landing on the column but not on its own dial. Only a matching colour and dial will lock in.

This is only the first of three symbols the second trial asks for, and the rooms that follow lean on the same ideas — burn the corruption, read the colour on the target, then work backwards from it. Once green and red click into place in two moves each, the four-link blue chain stops feeling like guesswork.