Christopher Lee returns to voice Saruman in The Lord of the Rings: The War of the Rohirrim, but this isn’t an A.I. situation.

We knew that Saruman would appear in The Lord of the Rings: The War of the Rohirrim, but we didn’t know who would be voicing the White Wizard. Turns out, none other than Sir Christopher Lee will return to voice Sarumon in The War of the Rohirrim. As Lee sadly died in 2015, you might expect this to be an A.I. situation, but fear not, the production has made use of archival recordings of Lee.

While speaking with The One Ring, Lord of the Rings screenwriter Philippa Boyens said they reached out to Birgit Kroencke (Lee’s widow who died earlier this year), who gave her blessing. “[Kroencke] said the thing that I think that Peter [Jackson] felt in his heart, which was that actually Sir Christopher would’ve wanted this.” Boyens said. “So we went into his records, I got to go back and hear his voice–not just doing the lines, but talking to us as we were recording him.“

Boyens continued, “We based it on a line from The Hobbit, which is, ‘Are you in need of assistance, my lady?’ [It was] a version of that line, and we thought, okay, that’s a line we can see how many takes he did of that. Can we use it? Can we find a new read on it and change it up a little bit? And our brilliant guys did that. But it is an authentic bit of Christoper Lee performance that it’s based on that line.” She added that they weren’t sure if they could even find the line, so they did look into casting a sound-alike. However, she was grateful that they were able to let Lee “use his own voice” in the role.

The official synopsis for The Lord of the Rings: The War of the Rohirrim: “Set 183 years before the events chronicled in the original trilogy of films, “The Lord of the Rings: The War of the Rohirrim” tells the fate of the House of Helm Hammerhand, the legendary King of Rohan. A sudden attack by Wulf, a clever and ruthless Dunlending lord seeking vengeance for the death of his father, forces Helm and his people to make a daring last stand in the ancient stronghold of the Hornburg—a mighty fortress that will later come to be known as Helm’s Deep. Finding herself in an increasingly desperate situation, Héra, the daughter of Helm, must summon the will to lead the resistance against a deadly enemy intent on their total destruction.“

The voice cast is led by Brian Cox (Succession) as Helm Hammerhand, the mighty King of Rohan; Gaia Wise (A Walk in the Woods) as his daughter Héra; and Luke Pasqualino (Snowpiercer) as Wulf. Miranda Otto reprises her role as Éowyn, the Shieldmaiden of Rohan who serves as the tale’s narrator. The War of the Rohirrim will hit theaters on December 13th.