12x04 Robot Part Four [2nd watch]
The fact this episode is entirely made up of climax is a reminder of how sometimes (often?) classic Who was constructed as a movie split into parts. As for Robot itself, I think the first half is very good and there are excellent ideas and concepts throughout, but some of the execution (both in the writing and realisation on screen) is a let down in the latter two instalments.
Next time on Doctor Who: Peter Capaldi goes Into the Dalek...
1x07 A Rebellious Woman
1x09 (28/8/14 edition)
[Watch it (again) on iPlayer.]