Part 1 (of 4)
[Watch it (again) on iPlayer.]
Well, that has to be one of the least-surprising Great Big Twists ever attempted. The main thing to wonder is: how's there another three episodes' worth of plot left?
Cunningly, the BBC have got around the odd-number-of-episodes-in-double-bills conundrum by airing a behind-the-scenes special before episode 11. One has to wonder if it would've been better placed before episode 13, but there you go.
[Watch Seep and Snap (again) on iPlayer.]