Didn’t we already have a taste of that, in Under the Lake/Before the Flood, with the writing in the ship?
Can I flash back to last week for a minute, since I was reminded of it by the re-run showing? (And because I want to forget this week’s episode already)
Paraphrasing:
Clara: So you must have thought I was dead for a while.
Doctor: Worst month of my life
Clara: Shouldn’t have been that long
Doctor: I’ll be the judge of time
Random exchange? Or did the Doctor actually pop off during the battle and do something?