Contains spoilers for this episode and earlier episodes.
Geralt and Yennefer attend the ball before the conclave, listening to warnings and offers while looking for evidence against Stregobor. Their conversations later reconstruct the evening from different points of view. Triss and Istredd share their suspicions about the missing novices and the Book of Monoliths. Geralt and Istredd stage an argument to draw attention while Yennefer enters Stregobor's rooms. His safe contains the book and possessions belonging to the girls, giving them grounds to confront him before the other mages.
Stregobor admits his campaign against elves but denies directing the experiments or hunting Ciri. Tissaia and the others arrest him, apparently ending the immediate investigation. Geralt and Yennefer return to the details that still do not fit. Jewellery links Lydia to the rare stone in Tissaia's bracelet, a gift from Vilgefortz. A painting Vilgefortz showed Geralt also recalls the coast where Yennefer was attacked after her portal was diverted. Together, the clues point to the mage they have overlooked.
They recognize Vilgefortz as the person behind the conspiracy while the gathering is already moving toward violence. Yennefer stays to locate Tissaia and warn her about the man she loves. Geralt leaves the room to investigate the sounds outside. Dijkstra catches him with a blade at his throat and tells him he should have chosen a side, ending the night before either can act on the discovery.