While I’m not planning to go into a lot of plot details, it’s likely that the random mutterings that follow will reveal some things you might prefer not to know if you haven’t seen the episode yet, so in my usual way, I’ll include this warning:
This is the middle part of what’s being described as a trilogy rather than anything so old-fashioned as a three-part story, so I may have to go into more detail next week, but here are my thoughts so far.
In Extremis, we learned of some singularly unattractive aliens who’ve been running simulations of all activity on Earth, to such an extent that they know everything about us. And since there’s no point gathering lots of data if you’re not going to use it, that’s just what they decide to do.
Now these aren’t your normal invading aliens, they’ve got something else in mind, which starts with a 5,000 year old pyramid appearing overnight in a politically sensitive area. The Monks, as they’ve become known, announce that the world is about to come to an end, but they can help if someone with “power” consents to them (a) helping and (b) err, taking over the planet. And to make their point, every clock and phone on the planet is turned into the Doomsday Clock, set at two minutes to midnight.
The Doctor isn’t all that keen on the idea, and suggests not doing that. Having managed to cancel World War Three (or at least postpone it), he’s a little surprised to find that the Monks are still looking forward to a bit of planet shopping.
After some thinking, and some Extreme Cleverness involving CCTV, he works out that the world is going to be destroyed by an escape of a virulent modified bacterium. More Cleverness follows with a solution found to the problem, with only one slight drawback. Still having a slight vision deficiency, the Doctor can’t see the dials on the curiously manual combo lock that’s keeping him in the lab that’s about to blow up.
Desparate to save him, Bill takes extreme measures…
All of which sets us up for something interesting next week.