"Extracting genetic material. A mutagen can be prepared from it. Administered to a witcher, it makes them temporarily more ... harpy. They stink, but they have excellent eyesight."

Geralt scrubbed at the back of his head with a bloodied hand. Then, carefully, sifted through the detritus to pull out a gold crucifix on a chain.

And, more importantly, a faintly humming moonstone cabochon set in silver. He tossed it to Bull.

"Smell familiar?"