Royce Pierreson has been bringing the mage Istredd to life for three seasons now on Netflix’s The Witcher series. Istredd also appears in The Witcher books by Andrzej Sapkowski, but his character received a significant expansion in the show as in the books, he’s primarily relegated to the short story “Shard of Ice” in Sword of Destiny.

However, one thing remains the same between the two iterations: Istredd’s love for Yennefer (Anya Chalotra). Beyond that, Istredd’s focus in the show has been on the mysterious monoliths around the Continent. In the second season, he and Geralt (Henry Cavill) helped link the monoliths to Ciri’s (Freya Allan) magical abilities.

Come season 3, Istredd has started working more closely with another Aretuza sorceress, Triss Merigold (Anna Shaffer), to find and protect the Book of Monoliths, an ancient tome dating back to the time before the Conjunction of Spheres, which has knowledge pertaining directly to the monoliths and how to use them to gain access to other spheres. In the wrong hands, this book could be especially dangerous.

Istredd and Triss had already searched for the book in Aretuza’s library before deducing that someone had stolen it. During the conclave ball, they find it in Stregobor’s (Lars Mikkelsen) safe, leading everyone to believe he is the traitorous mage experimenting on elven apprentices.

By the end of The Witcher season 3, part 1, the truth is revealed, and we learn that Stregobor was likely framed and Vilgefortz (Mahesh Jadu) is the one behind everything.

When the Thanedd coup begins at the start of The Witcher season 3, part 2, Triss tells Istredd to retrieve the book from the safe before anyone else can take it. Just as Istredd goes to get it, Vilgefortz intervenes, revealing himself as the traitor. Before Istredd can do anything, Vilgefortz sends him and the book to an unknown location through one of his portals.

We do not see Istredd again for the remainder of The Witcher season 3, but there’s no way that he’s dead. It’s unclear where Vilgefortz would have sent Istredd, but he needs him in addition to the book.

Earlier in the season, Yennefer got trapped in one of Vilgefortz’s portals and ended up in a strange place where an illusion of Geralt tried attacking her. Vilgefortz likely sent Istredd somewhere similar to hold him until he finished his business on Thanedd or straight to Nilfgaard to be imprisoned until further notice, probably the latter since we see Vilgefortz standing next to Emhyr in the court at the end.