After last time's shocking end, we spend a lot of this episode dealing with the aftermath. Not only is Colonel Christopher Ibrahim dead (you bastards), but everyone on the diplomatic mission was also killed by what apparently was a massive sonic bomb triggered by Ted. Everyone, that is, except Barclay, who was saved by Salt when she raced him to the surface while maintaining hyperbaric pressure in his lungs via mouth-to-mouth contact. (I assume "hyperbaric" was added after someone pointed out that Barclay would likely be seriously injured from the rapid decompression accompanying his speedy ascent.) So while he and Salt get picked up by a UNIT helicopter in the ocean, Kate has to deal with the fallout of the assassination attempt -- not only the death of Christopher and the fact that someone targetted her, but that the diplomatic conference was destroyed by a bomb and that Salt is apparently claiming credit. (Of course, we know that's been faked because we've seen Salt's actions the whole time, but that doesn't mean the rest of the world has.) Jemma Redgrave does an excellent job, as the focus of the show shifts from Barclay to her, with showing a wide range, from grief over Christopher to steel over handling the assassination attempt to calm as she's forced to negotiate with the new Aquakind ambassador, Tide, who threatens to escalate the war if Salt isn't turned over to them for the crime of saving Barclay over fellow Aquakind. Redgrave handles all of these very well, often shifting between them in the same scene. It's very well done. (Plus, we get an offhand reference to a hitherto unknown daughter in Dubai, which is fun.)
But then it turns out that both assassination attempts (Kate's and the Homo aqua people) is the work of some new fanatical group called the Institute of Las Clemente who are concerned with the Great Replacement Theory (which in this case is being replaced by Aquakind instead of minorities, but the parallels are clear). The evil American general makes quick work of them, so it's not completely clear at this stage what the point of this second group is. Is it to show that there are other violent groups out there, not just the warmongering cartoon villains with the ear of the Prime Minister? Or was it just to have some action at the halfway point that didn't immediately implicated Sir Keith and company? As it currently stands, it's just a touch awkward.
But because there's this deepfaked video of Salt claiming responsibility that they don't prove is deepfaked until the end of the episode, Kate is forced to take Salt into custody of a prisoner of war. Obviously this upsets Barclay, so he takes matters into his own hands and helps her escape, following her into the river as a fugitive. In other hands this new bravery might feel inconsistent, but Tovey makes it a natural growth of the character. This new fugitive life also gives Gugu Mbatha-Raw a chance to show a more playful side of Salt. Before she's been primarily the diplomat, serious and resolute, with only hints of something else, but once she's no longer in that role, Salt becomes more light-feeling, marvelling at glass and finding herself attracted to Barclay. To their credit, Tovey and Mbatha-Raw continue to play this well, with both confusion and desire for Tovey and playful romance for Mbatha-Raw. Not that it lasts long, since Barclay isn't as clever at evading UNIT as he thinks he is -- which honestly makes sense.
The other thing to note is that our cartoon villains are still out there but being a lot less cartoony this time around. Instead we have the American General taking charge, having Sir Keith murdered because he was involved (possibly coincidentally, though that's not certain), rounding up the Las Clemente people, and taking command of the British army (with the PM's blessing) so that they can capture Salt and run experiments on her, either alive or dead. That does lead to a tense standoff on a bridge, as Kate is willing to shoot British soldiers rather than let the US General (I should probably learn his name; hold on... apparently it's Gunsberg? Well that's subtle) take custody of Barclay and Salt, which is only resolved when Salt temporarily paralyses everyone (except Barclay, oddly) with some special scream and then dives into the river.
So with one episode to go, I'm genuinely not sure how they're going to resolve all this. But between this and the last episode, things are definitely looking up, entertainment-wise. It's possible it could all collapse at the last minute, like the last two Doctor Who season-enders Davies wrote (since he's also writing the wrap-up for this series), but if they maintain this level of quality then this miniseries will have been worthwhile. Fingers crossed...