Doctor Who 809: Flatline

This review is overall spoiler-free!

World-Building: Awesome
Characterization: Great
Plot: Great

This was a thoroughly enjoyable episode and I, like many others, would love to see more from writer Jamie Mathieson after his great work on these last two episodes. The story is well-paced, creative, and I personally found it more thrilling/creepy than the shambles that the supposedly scary "Listen" turned out to be.

MINOR SPOILER
My only criticism of this episode itself is Danny Pink's use of the b-word to Clara. I'm not sure in which universe this is supposed to be OK, but it's definitely NOT OK in the universe I live in. To be fair, I didn't hear this the first time I watched the episode but realized it later after reading other internet comments, so I am open to the possibility that it was something else that we heard wrong/mistook for the b-word, though I really can't think what that would be...
END OF MINOR SPOILER

In terms of the character-long season arcs there is still something wrong about Clara and Daniel's relationship and I said in my review of last season's episode, the problem is that their relationship is happening off-screen. A lot of people are hating on Daniel Pink himself, but I personally think that it has nothing to do with the actor or the character, just the omissions, those missing scenes between him and Clara that we aren't being allowed to see. I put that squarely under Moffat's responsibility, because as the show-runner he's supposed to be looking after the season-long development and making sure the ending of one episode meshes with the beginning of the next and so on.

At the end of the day, I'd consider this one of the best episodes of the season and actually one of the best episodes of Moffat's run! Definitely a must-watch!