WARNING! THERE MAY BE UNMARKED SPOILERS!
- Do Not Do This Cool Thing: Behind the Scenes example: Matt Smith relates that he and Jenna Coleman were told not to swing on the bars during the TARDIS's fall to Trenzalore. So what does Matt Smith go and do? Swing on the bars during the TARDIS's fall to Trenzalore.
- Hilarious in Hindsight: The 2015 Christmas special revealed that by the time of her death in the Library, River had not only already met the Twelfth Doctor, but he was the one who truly returned her love for him, staying with her for twenty-four years on Darillium. It is therefore very possible that, despite not letting on, she already knows at least something of Clara's future. This adds extra humour to her realization that the Doctor had given Clara the impression that River was a man!
- I Knew It!: A few fans successfully guessed the revelation regarding Clara: that the modern London Clara is the original and somehow ends up splintered across time to save the Doctor's life countless times.
- They Wasted a Perfectly Good Character: The Whispermen have an incredibly creepy design (with, as mentioned, a very Slender Man-esque vibe) and a fairly menacing presence in the first half of the episode, complete with an Ironic Nursery Rhyme in the associated minisode. Too bad they end up being little more than disposable spare bodies for the Great Intelligence.
