It took me a long time to really get into this episode. I listened to it on a road trip this past weekend, so my lack of focus may have been because of that, but once I finally caught on to what was happening I enjoyed it to the end.
Is it weird to say that I found the denouement more satisfying than the rest of the story? Yes, the adventure with the underground dog-bugs (dugs? bogs?) was exciting, and, since this was my first Balfour and Meriwether story, the two heroes' prowess in dealing with all challenges was pretty delightful; heck, even Meriwether's coming out to Castor at the end was very moving (perhaps I wasn't listening closely enough earlier in the story, but I do find it a little strange that Meriwether would go for a full-on snog as his way of confession; I didn't pick up on anything that might have suggested he was attracted to Castor, and without that detail I find myself wondering if the scene is problematic in suggesting that any two gay men will instantly find each other attractive based purely on their knowledge of each other's sexuality). But for me, it was the discussion of empire that turned the whole story on its head and made everything before it more interesting and not just a send-up of Victorian adventure.
I think I was most impressed by the parallel between how England allied with the dugs (definitely going with dugs) out of convenience despite being repelled by their nature and the same alliance that Meriwether made with Castor in order to save Balfour and Winters. There's some interesting subtext here related to disliking those things in others that we recognize in ourselves, and I wonder if the point is supposed to be that England is not only wrong for using the dugs like this, but also in denial about its own political nature. Perhaps if England could have acknowledged that it was dealing with a sovereign nation that had its own ambitions, then maybe the alliance could have been more amicable rather than utilitarian. I suspect that's the reason Meriwether and Castor part on decent terms, where England and the dugs end up going to secret war.