Feels straight out of season 8, not just in terms of the timeline with the Coal Hill stuff, but also the doctor’s characterisation. The story itself I think is a bit on the worse side but it’s still solid, but the main thing is I feel this could fit very easily into a season 8 rewatch, setting up 12’s involvement with UNIT, hinting towards the actions Clara takes in Dark Water, and the character stuff for 12 is on point for his arc that season trying to figure out what type of man he is.