Hmm. I was honestly less of a fan of this episode than I was hoping I would be. There were a few elements of it that just really bothered me.
Cons:
The big one is... Kate? Like? Girl, what the fuck? I'm really okay with U.N.I.T. being controversial and with Kate making bad choices, that's totally valid and interesting. But her letting the Shreek out to attack Conrad was so wildly out of line that I was waiting for it then to be a much bigger than it was. This should have been a thing where people were horrified and demanding she step down, right? And instead she and Ruby have a sweet little moment and share a hug and there's a quip about Ruby "collecting mothers" and I was just staring at the screen like... what now? What? She just did something absolutely insanely awful, siccing that monster on a human being. I know he's a shitty human being, but still. What kind of responsible leader of a para-military monster-hunting organization would do that?
I also didn't really like the scene with Conrad and the Doctor. That little speech about how the Doctor is fighting a constant battle to protect people who just want to be safe... I don't know. It felt very Moffat-era Who to me, in the sense that in those seasons the Doctor was very much cast as a brave soldier hero type, which is... not who this character is. The Doctor protecting people when he encounters people who need protecting is of course part of who he is, but I don't know how I feel about the characterization that he's fighting a constant battle. Feels strange to me.