Denis Villeneuve’s first Dune film is a sweeping epic that introduces a new take on Paul Atreides at the beginning of his path to becoming a legend, but the movie’s careful to keep a number of details and characters from Frank Herbert’s original novel shrouded in secret. It was obvious that Villeneuve was holding some things back to surprise audiences with in Legendary’s second Dune movie, and the latest bit of casting news suggests that the director knows what he’s doing.

Deadline reports that Christopher Walken has signed on to Dune: Part II to portray the Padishah Emperor Shaddam IV who is initially responsible for sending Paul Atreides’ father Leto to the planet Arrakis. In Herbert’s novel, House Harkonnen and the emperor are both shocked when they learn of the Fremen’s continued resistance on Arrakis following an attempt at eliminating House Atreides. Considering how Dune: Part II is meant to cover elements from the book that the first film didn’t get around to, the emperor’s not going to be the only interesting new part of the story. But he’ll definitely be one of the most important parts when Dune: Part II hits theaters on October 20th, 2023.