Overview
Turn and Face the Strange is the Blood and Wine secondary quest that unlocks mutations. Soon after Blood Run, a boy in Beauclair delivers a letter to Geralt. It comes from Triss if he romanced her, and otherwise from Yennefer, worded differently depending on their relationship. Tipping the boy 5 crowns counts as a Proof of Generosity for There Can Be Only One.
The robbed grave
The letter points to a grave in Orlémurs Cemetery, just west of the signpost. Someone got there first. Follow the robber’s footprints until the trail goes cold, then consult the old map of Toussaint in the inventory. It leads to a lake, where an underwater portal takes Geralt into ancient ruins.
The ruins
Climbing down through the ruins, Geralt fights panther statues that turn out to be spectral guardians, and finds signs of the grave robber and pages from Professor Moreau’s diary. A sealed door opens when the blocks on the walls are shot with the crossbow. In the chamber beyond, a gargoyle comes to life and drops a stone hand. Placed on the pedestal, it opens a set of portals. The right path follows the gaze of the central statue and ends in the laboratory.
Moreau’s laboratory
Find the two missing crystals, one on the desk with a book and one on a bench behind the iron maiden-like machine, and fit them into the megascope. The recordings reveal what Tomas Moreau was doing: trying to undo the mutations of a witcher to cure his son, he only made them stronger. The process needs the eggs of a giant centipede. Extra recordings earn more experience.
The albumen
A hole in one of the cages leads to a cave full of pale widows, which Yrden leaves helpless. Take one dose of mutated giant centipede albumen from the nest and bring it back to the machine. Geralt strips, climbs in and endures the process, which unlocks mutations. In New Game Plus, where mutations are already unlocked, he gets an extra skill point instead. A portal activated with Aard carries him back to the lake.