I know a lot of people who didn't like 42, but it's actually one of my favorite episodes of the 3rd season. It's not often that we get to see the Doctor helpless and scared out of his mind, so it's interesting to see that happen. And of course, it gives Martha an opportunity to shine. I do agree though that the timing is a bit off-there's no way they could've gotten through all those doors, not at the pace they were moving. Still, it doesn't ruin the episode-Doctor Who requires the suspension of disbelief quite often, it's just something that goes with the territory, I suppose.
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