In 1979, The Hitchhiker’s Guide to the Galaxy author Douglas Adams was enlisted to pen a script for the finale of Doctor Who’s 17th season. Titled “Shada,” the episode saw The Fourth Doctor (Tom Baker) and his companion Romana (Lalla Ward) land the TARDIS in Cambridge to help a retired Time Lord stop an evil alien from hacking into the secrets of a lost planet-turned-prison for evildoers.

The script was written, and filming for the episode commenced … but then there was a BBC staffer strike, and filming was abandoned. Now, nearly 40 years after its intended air date, Whovians will finally get to see the episode—just as Adams wrote it and with Baker stepping back into the role.

BBC News reports that “Shada” will finally see the light of day when the original footage is mixed with animated recreations and newly recorded voiceovers from both Baker and Ward to complete the episode.

Baker, for one, is thrilled to see the episode finally reach audiences; he told BBC News that it was one of his favorite Doctor Who stories.

"I have many fond memories of shooting the location scenes in Cambridge, and it was disappointing not to finish the story in studio,” Baker said. “I'm so glad that BBC Worldwide have found a way to bring fans a complete visual version.”

It’s not the first time the network has recreated one of the series’s old episodes. In November 2016, “The Power of the Daleks” found new life in animated form 50 years after it first aired, and more than 40 years after its original recording was destroyed.

At this point, “lost” episodes are as much a part of Doctor Who canon as doctor regenerations. When the sci-fi series first began airing in 1963, little thought was given to how—or why—there would be any reason for the BBC to stockpile the original recordings of their shows when they could just reuse the same tapes to save money.

While fans have helped the network to reassemble parts of the missing catalog, more than 100 of the series’ original episodes remain lost to time. Fortunately, “Shada” will no longer be one of them. The episode will be available for digital download on November 24 and released on DVD and Blu-ray on December 4.

[h/t: BBC News]