Warner Bros. has yet another Lord of the Rings movie in development — tentatively titled The Lord of the Rings: Shadows of the Past — and we have Tolkein superfan and soon-to-be-former-The-Late-Show-host Stephen Colbert to thank. Colbert and Lord of the Rings trilogy director Peter Jackson revealed Wednesday that they’re working together on an adaptation of material from The Fellowship of the Ring that never made it into Jackson’s film.

In a video posted across Warner Bros.’ social media, Jackson first offered update on Andy Serkis’ The Hunt for Gollum, saying, “It’s looking amazing. The script is coming together really well, and I think it’s going to be a really good film.” Jackson then announced “another film that we’ll be making after The Hunt for Gollum,” and welcomed a “very special partner” in Colbert.

Colbert then explained the project, which he says will be based on a chapter from The Fellowship of the Ring: Chapter VIII, “Fog on the Barrow-Downs.”

“You know what the books mean to me, and what your films mean to me,” Colbert told Jackson. “But the thing I found myself reading over and over again were the six chapters early on in The Fellowship [of the Ring] that y’all never developed into the first movie back in the day. It’s basically the chapter ‘Three is Company’ through ‘Fog on the Barrow-Downs.’ And I thought, ‘Oh, wait, maybe that could be its own story that could fit into the larger story. Could we make something that was completely faithful to the books while also being completely faithful to the movies that you guys had already made?'”

Colbert said that he started discussing the idea with his son, screenwriter Peter McGee, developed a “framing device for that story,” and pitched it to Jackson. They then teamed up with Philippa Boyens, screenwriter on the Lord of the Rings and Hobbit trilogies, and got the green light from New Line and Warner Bros.

Here’s the synopsis for The Lord of the Rings: Shadows of the Past, as reported by Variety:

Fourteen years after the passing of Frodo – Sam, Merry, and Pippin set out to retrace the first steps of their adventure. Meanwhile, Sam’s daughter, Elanor, has discovered a long-buried secret and is determined to uncover why the War of the Ring was very nearly lost before it even began.

The Lord of the Rings: Shadows of the Past does not have an announced release date. The next film in the franchise, The Hunt for Gollum, hits theaters on Dec. 17, 2027.