Frankly, this episode is bonkers. Genuinely, I’m used to the way that Doctor Who works - able to go anywhere and do anything, adapting its format to suit any story you care to tell - but I’ve come away from today’s episode with a headache. It’s all so... odd.

To start with, you’ve got the Doctor being arrested. Now, that doesn’t sound particularly out there, but it does look very unusual to see Tom Baker’s Doctor being directed into the back of a police car. I wonder if it would have felt less unusual with the Third Doctor, considering how used to seeing him on Earth I was? This incarnation has spent more time on contemporary Earth than I expected him to, but even then it’s in places like laboratories, or old houses (sometimes, both): it’s rare to see him in such an ‘everyday’ situation as this. That’s not a complaint - it’s actually quite interesting to see him like this. I know he can talk his way out of a showdown with a monster, but you almost wonder how he’ll pull of escaping from the police.

It’s after that that things start to go really off-the-wall. The Doctor reasons that the Master’s TARDIS must still be inside his ship somewhere. Ok, that’s quite neat idea. You could use that as the basis of a story in itself (a short one, perhaps...) as the Doctor and Adric get caught up in a chase around ever-moving TARDIS corridors in the hunt for their foe. What’s barmy is his realisation that the only viable solution is to materialise underwater and use the force of that to flush the Master out of the ship. I genuinely cannot get my head around this. For a start... where’s the Master going to come out? Is there a back door large enough for the water to force him out of? How does the Doctor think he’s going to cope after that, with a ship full of water? Does he really think that he and Adric can simply hold on to something to avoid being washed away? Absolutely bizarre.

In fairness, though, it leads to a couple of wonderful moments, and the ones that I enjoyed the most in today’s episode. First, the Doctor tells Adric that they’ve managed to perfect a nice soft touchdown. Seconds later, the ship lurches, and they’re thrown to the ground. There’s something about the timing of that sequence that just really works, and had me laughing. Then the image of the TARDIS having materialised on the boat is also wonderful, as is the shot that follows, of the Doctor spotting the white figure on the bridge overlooking them. It’s a great image when he goes to speak with this watcher, and you simply see the Doctor hang his head. Really quite striking, and probably the first time that you get a real sense that the end is fast approaching.