I'm always a fan of Paul Magrs, though he has a rather particular format. A mad, over-the-top (and sometimes hard to follow) plot; bonkers ideas pulled together into some sort of sense with Iris Wildthyme swanning through the plot like a chaotic juggernaut.

The Wormery follows this format, but it's not quite as successful as Magrs' other work. There's an oddly grim tone to the whole thing, rather than his usual tone of surrealist comedy. The framing device an elderly Mickey telling the horrid tale to a mysterious investigator (who later turns out to be the Seventh Doctor) adds a layer of abstraction to an already overblown plot, and the layers of inter-worm (and shadow) politics leads the plot to be rather all over the place, and not in the fun way.

Iris having her own Valeyard-esque figure in Bianca isn't necessarily a bad choice; I just wish it were better executed. That said, I wish that the Valeyard himself were better executed as a dark reflection of the Doctor, too. Neither the Valeyard nor Bianca feel like a reflection (however twisted) of the character they purport to be – they just feel like rather two-dimensional baddies. Perhaps this is just personal preference, though. I can see how a dark reflection of Iris would be obsessed with order and stability, but I am fonder of a dark version of the character having their existing flaws twisted and exaggerated into wickedness, rather than being a simple opposite.

All that said, The Wormery is still a decent episode. I was never bored throughout it; it always had something fun to throw at me. Was it all one elaborate way to make an episode about wormholes having actual worms? Perhaps. But I find that sort of thing hilarious, so I won't complain.