BBC Worldwide is finally releasing this week its reassembled version of the infamously unfinished Doctor Who adventure, Shada. It’s been a long time coming, and is likely to be the closest we’ll get to a definitive version of the tale.

The story, penned by Douglas Adams, began filming in 1979 with Tom Baker in the role of the Doctor. And whilst footage would air as part of The Five Doctors a few years later, the story itself remained incomplete. That was because of a strike at the BBC that brought an end to production. And production never restarted, with lots of scenes left unfilmed.

The new release, though, has filled in the gaps by replacing the unfilmed segments with new animation, voiced by Baker and Lalla Ward.

Shada is available to buy digitally from the end of this week, and a DVD and Blu-ray edition will go on sale at the beginning of December. Here’s the trailer that’s been put together…