Brilliant episode, one of my favourites actually
Spoiler:
Samaritan just gets creepier and creepier, sending hidden codes over radio transmissions and perfectly cloning voices to fake suicide messages now.
I loved that they gave the story a bleak ending with Max being killed rather than a tacked on hopeful resolution, it really drives home how dangerous the the threat of Samaritan is. And the twist with the assistant being a Samaritan operative all along was brilliant (and terrifying since it hammers home that they could be hiding anywhere in plain sight).
I also love any time they bring up the moral dilemmas regarding The Machine.
The Shaw scenes were great too, her shooting the doctor thinking it was another simulation then finding out it was real
.