Yes, the 7-hour layover at Heathrow did me in. The total trip took 28 hours and 48 minutes, during which I slept a couple of times but not well.
Another thing I learned: it's hard to fix a laopto when they don't let you have tools in your carry-on bag. It appears that the connection between my laptop's monitor and its video chip has come loose. The screen appears to be missing half of its pixels, but otherwise it still works. A loose cable is the best case, anyway; the worst case—the monitor itself has died—requires me to get a new laptop. I'll have to try fixing it after my macroeconomics exam, which starts in 13 hours and for which I am woefully unprepared.
So, even though I have a few minutes right now, without a working monitor I can't really prepare any photos. Otherwise I'd have art. I'm digging the hotel room, I must say.