Surprisingly good for a studio colony story. The costumes are trash and there's an abandoned side story about rebellion that only serves as poor colouring for the society, but besides these it comes together rather well. Davison sparkles with charisma unlike any previous story (but quite like how I have become used to his Doctor in audios), and Strickland gets to do something different with his panic attack from encountering the Tractators, whose machine is a bit hokey but still horrible to see in action, and whose hive mentality is a clever conceit without pushing Bidmead into his usual science fixation. The set & music gives a nice grime, and the guest characters are somewhat forgettable but share interesting traits to distinguish them from other stories. Hell, I'll even let JNT off for the false 'destroying the TARDIS' because seeing the sets mixed in with the rock was really striking.