I had a good amount of fun with this short story.  It was neat getting what felt like an origins story for Osgood, I like the ties this has to the Sontaram Stratagem two-parter from the show, and it was a lot of fun exploring the "Grey Archive" as a setting.  I really liked the idea of different archives, like the Blue Archive and Grey Archive, which have different purposes and roles when compared to the already established Black Archive.  That's very good world-building and Dave Rudden shows he is a creative individual who has a lot to offer as the writer of this story.

Beyond that, it is a very simple and straightforward take on the "base under siege" formula all too common in Doctor Who.  At least the whole angle of Sontaran clones being not fully developed was a lot of fun.  It's not amazing, but it is fun enough and a pleasant listening experience overall, even if it felt pretty predictable.  Plus, as always with the Wintertime Paradox, if you listen to the audio version, Sophie Aldred very much enhances the experience overall with her voice work.  It really feels like she is able to inhabit all these characters and adds so much to the story.