Doctor guy is like, "Don't worry, Doctor, I'm only neutralizing your ape bacteria, the hideous torture and experimentation comes later," and the Doctor calls his attention to the fact that he is clearly not human, and is about to die. Restac is not having that, and tells the doctor to keep going, but he stops. The Doctor goes right back to being adorable. "Oh, that's much better, thanks! Not got any celery, have you?" (Zing!) He makes a joke about the climate down there being better for tomatoes, and then introduces himself and Nasreen, who wakes up and woozily exclaims, "Oh, a green man!"
The Doctor's friendly with Restac, which is a lost cause, and he's a bit disheartened to find out she's a military commander: "Really? There's always a military, isn't there." They discuss how the drill seemed like a weapon, "attacking the oxygen pockets" upstairs in the earth, and the Doctor is first impressed with their science but then worried by the whole drill thing: Finally, the answer to Alaya's initial aggression.
Restac asks for/demands info on the rest of their "invasion force," and he's just lovely saying it's only him and "lovely Nasreen," looking around for the folks they kidnapped. And, of course, to offer Alaya's safe return, as a closer look reveals their sisterhood: "Of course you're worried, but don't be, she's safe." Restac points out the very good point that it's sort of crummy to say you come in peace and then immediately take hostages, but the Doctor tries to explain that's not the deal. What is the deal? Restac does not give a fig. "I don't negotiate with apes. I'm going to send a clear message to those on the surface: Your execution."
And again, Restac could be totally cool, because you can see her point: She's been woken up from a very long sleep because something is threatening them -- something that, even if the Doctor explained it, would still make little damn sense, because "a jolly big hole" is not actually a scientific pursuit -- and now they've got her sister and they're making all these demands without proving anything other than what she's been led to presume, which is a war. But instead, it's a one-sided conflict between nice little white families and a bunch of unfeeling monstrous invaders whose technical claim to the land is never more than provisionally granted in order to make this whole grody story work without actually resolving anything.
Meanwhile, Amy and Mo have found some very scary other chambers -- this is like every childhood memory I have, of this show and like The Third Eye, in one very cheap set, with the spotlight shining down -- containing suited-up Silurians still in stasis. Terrifyingly, they crack a couple open and sort of mannequin their way around in there, hoping not to wake them. Amy somehow figures out that they are standing on "some sort of powered transport discs," and offers to take Mo home to find the Doctor, who's presumably still upstairs crying over a hole.