Gaetan is a witcher of the School of the Cat. Even after years on the Path, he still remembers his younger sister fondly. His school has fallen on hard times: a letter from his fellow witcher Joël warns that soldiers overran it, that at least two witchers are dead, and that there are bounties on both their heads. Gaetan went into Novigrad anyway, leaving a shaelmaar trophy with the bookseller Marcus T.K. Hodgson as collateral.

In The Witcher 3

In Velen, Gaetan took a contract to kill a leshen plaguing the village of Honorton. When the job was done, the ealdorman offered him twelve crowns and lured him into a barn with a promise of the rest. It was a trap, and a pitchfork nearly killed him. Wounded and furious, Gaetan slaughtered everyone in sight, guilty or not, sparing only a little girl, Millie, who reminded him of his sister.

In Where the Cat and Wolf Play…, Geralt pieces together what happened in Honorton and finds Gaetan nearby, still nursing his wounds. Geralt suspects it was not the first time; Gaetan admits nothing. The witcher must then decide what to do with him.