Loved Part One, The Impossible Planet, but whoops, what a disappointment part two 'The Satan Pit' is. The cliffhanger of something apparently rising out of the pit was - nothing coming out of the pit. Then ages spent crawling round air vents to pad out the story, the Beast a roaring thing empty of intelligence, so no Doctor/villain confrontation I'd been anticipating. The TARDIS is somehow inside the pit despite the pit not being open till long after the TARDIS fell through the planet crust. And finally another ready made solution which existed for no logical reason - I mean, why not plunge the Beast into the Hole as soon as the pit opened? Why not plunge him in all those years ago instead of imprisoning him anyway. Why not - I could go on but I've lost interest...