In the 39th Century, Roz Forrester has got a new partner. Roz is an Adjudicator on Earth, a police officer at the heart of a cheerfully bigoted, more than slightly small-minded Empire. Her new partner, Chris Cwej, is younger, more enthusiastic and, presently, furry. The latest craze on Earth is Body Beppling, changing your genetic structure how you fit.

Oh, and murder.

For all the Empire’s brutality, Earth itself should be a paradise. An entirely spaceport-covered one but a paradise nonetheless. So when Roz and Chris catch the latest in a string of murders they get worried. And when they discover the first hints of the conspiracy underlying them, they get very, very worried. And then they meet the Doctor and Bernice, on Earth due to the warning of a dying alien. Something terrible is coming. And Roz, Chris, Bennie and the Doctor are straight in front of it.

There’s a huge amount going on here and the story hits the ground running in a manner that’s both off-putting and gets your attention. Cutting between the two pairs of leads, Andy Lane’s story uses them to show a well rounded approach not just to Earth but to the idealistic politics Doctor Who sometimes embraces. This is a Gordian knot of a situation and one that there’s no entirely right way to resolve. One of the best closing scenes involves Bennie and the Doctor discussing exactly that and it’s a beautiful distillation of the 7th Doctor’s mindset. You never win completely. But sometimes you can win enough for it to matter.

That oddly fatalistic approach is neatly reflected in Roz and Chris too. Roz’s racism is a particularly well handled beat as is the real reason behind it. Lane has great fun with every toy in the ‘Space Cops!’ Box and does a lot of things you aren’t expecting with them. The plot twists and turns constantly too and this may be the most incident heavy New Adventures adaptation we’ve had to date.

The cast all impress, especially Yasmin Bannerman and Travis Oliver as Roz and Chris. Much like Charley with the 8th Doctor audio adventures and, of course, Benny, they feel less like companions and more like co-leads and the equal air time they get here with the Doctor is richly deserved.

However, the story does have some problems. The reveal on the main villain falls dangerously flat if you don’t know the early history of the show intimately well. It still works but instead of being a shocking reveal it’s more of a ‘Huh. Who’s that again?’ moment, a fact not helped by the character talking like a character from the early years of the show too. Likewise several of the alien characters, while extremely well written and acted, suffer from distinctly tongue-in-cheek accents. And not in the satirical way either: they actually sound like they’re talking around their tongues. None of the performances are bad, to be clear, but several pivotal ones are hurt by either a lack of familiarity or understandable, if not entirely successful, production choices.

For all that though, Original Sin continues Big Finish’s run of successful New Adventures adaptations. There’s a pleasingly balanced, blackly humorous (and depressingly timely) tone, some great ideas and performances and an absolutely stunning version of the theme tune. Plus given this is Roz and Chris’ introduction, it’s also a brilliant on-ramp for some of the other adaptations.

Verdict: Smart, timely, pleasingly dark and worth your time. 8/10

Alasdair Stuart