There’s a story that Olaf Pooley was really unhappy with the decision to turn him into a full-fanged green werewolf. I guess he’d understood that he would be turning green and going wide-eyed like the fellows in the earlier episodes, but in part five of this story, there’s a lot more goo from the earth’s core and a lot more heat, and this all combines to turn people into white-fanged slavering dog monsters with lots of hair. Our son pronounced these guys “really scary” and they sent him behind the sofa with a shriek.
There’s a really good moment early in this episode to casually remind everybody that the Doctor’s such a great hero. I love how he goes straight into the drillhead room with Derek Newark’s character, hoping desperately that there’s a way to stop the destruction. This isn’t his fight, and it isn’t his problem, and not one person on this hellworld has shown him a second’s consideration, but he’s still immediately willing to risk his life for them.