UNIT: Revisitations

A collection of three stories linked solely by the theme of UNIT facing a re-appearance of something they have faced before. Albeit, in two out of the three stories, not directly on TV. It's not the strongest set in the series, which seems to be running short of new ideas and isn't developing its leads as much as it might, but each of the stories has something to recommend them.

• Hosts of the Wirrn – We start with UNIT facing off against the Wirrn, which, of course, they only know about from Harry's reports of his experiences in The Ark in Space (although, in fairness to him, his report seems to have been quite thorough). Here, UNIT rather unwisely decides to experiment on a Wirrn egg they have recovered, and much of the story is told from the perspective of the entomologist they bring in from academia to help them. Naturally, things go wrong and build to a dramatic situation in the second half. There are plenty of references to the original story and quite a few moments of humour alongside the inevitable body horror. There's also an original take on the Wirrn's hive mind and some changes/enhancements on the basic format explained by them being a different ‘strain' than the ones seen thousands of years later on the Ark. There are a couple of weak points, however. Firstly, many of the characters spend a lot of time in hazmat suits that muffle their voices; they're easy enough to understand, but it's not a great effect for audio. Secondly, the solution, when it eventually comes, really doesn't make any sense, which is rather a pity given some of the effort in the rest of the story. 3 stars.

• Breach of Trust – The ‘returning' aliens here turn out to be ones that UNIT encountered in an untold story, meaning that they're essentially new. They are, admittedly, quite original, and the core concept is one that works well on audio. They are also, at least initially, ambiguous, and the focus of the story is on whether or not the alien that has walked into UNIT headquarters with an offer of help can be trusted. It moves nicely along, managing to do quite a bit in its one-hour length as we initially explore the mystery of what the alien is and why it's here and then onto a more typical UNIT threat – albeit one that cannot be countered with infantry soldiers. There's some good characterisation of the leads, showing their different approaches to what seems an impossible situation, although the sort of fallout that we'd expect from it in future episodes is unlikely to surface. 4 stars.

• Open the Box – Finally, we have an investigation into a New Age Wellness retreat that (of course) feels suspiciously like a dangerous cult. It's this story that features a monster from the original TV series and it's good to see that it's one that presents a more nebulous threat than, say, Silurians would. This uses an admittedly common SF trope to get inside the character's heads and explore what makes them tick, but it is one that's used well here. As is the initial mystery as to what our heroes are really facing – helped by the fact that, for various reasons, it's changed from the details that we saw before. While it doesn't have the action elements that the longer first story in the collection has, it has the advantage of working well with its shorter length and being an effective follow-up to a TV adventure that's often underrated and overlooked. 4 stars.