Black Mirror is great, and it's probably one of my favorite shows of the decade, but as an anthology series it is completely beholden to its individual episodes. So what I'm going to go ahead and do is react to all six epidoes from Season 4, individually, below. Spoilers obviously follow!
USS Callister
No surprise that the star-studded Star Trek episode is what they chose to go with for the opener. This was plenty enjoyable, a nice appetizer of sorts, but its main technological "what if" - the real hook for any Black Mirror episode - is just "what if a digital copy of yourself were sentient, just like you?" This was also one of the hooks in the Christmas episode with Jon Hamm and the beloved "San Junipero" episode, and to a lesser extent in the Domhnal Gleeson episode from Season 2 and the Wyatt Russell episode from Season 3. What I'm saying is, come on, think of something new, Black Mirror! There are other techno-futuristic bents that can scare the living shit out of someone. Props to the actors here though, and to the writers for making Jesse Plemons just a completely detestable angry fanboy nerd. Victims of '80s bullying tropes no more, I'm all for treating those people like the villains they are, going forward.
Arkangel
So, I saw one piece on Vulture call this the best episode of the fourth season, and I saw another piece also on Vulture call it the single worst Black Mirror episode of all time. I am - shocker - somewhere in between, though probably more positive than negative. This one's all about parental guidance and parental control features taken to their logical extreme - a monitoring system that not only tells you where your child is at all times, but can give you a live feed into their point of view. It progresses a bit obviously - of course the rising action here would involve a mother witnessing her teenage daughter having sex and taking drugs - but it's also vintage Black Mirror in its singular focus on a potential near-term technology and the way it'll surely ruin our relationships and lives.
Crocodile
Oh shit, Iceland! Love Iceland. Anyway, this one's dark! And not just because it takes place during an Iceland winter. Not really a whole ton to it beyond how if you break the law you've got to keep breaking the law to cover up that you've broken the law. This is one thing when it's like, tax evasion, but quite another when it's murder. It starts with an accident and a poor decision, then there's a cover-up murder, then before you know it it's a goddamn entire family of innocent people, killed in cold blood. Where's the technological aspect, though? It's here, but it doesn't really have a ton to do with the exponential murder spree; it's just a little chip that reads your memories - faulty though they are - and extracts information from them for things like insurance claims. Thing is, that's just a security camera! You're just turning people into faulty security cameras here - and it'd be one thing if that ended up being part of the plot, this idea that someone was being wrongly convicted of a crime because of someone else's faulty memory, but that's not where this one goes, at all. A fine episode, really, but a wasted opportunity to play with the ramifications of the techonology introduced! I'm nitpicking though, and I do also love the idea of an automated pizza delivery stand truck.
Hang the DJ
Here's this season's "San Junipero," right down to its spot batting fourth in the lineup. It's one of those classic episodes of Black Mirror that presents a weird alternate version of our reality and slowly pulls back the layers until you understand what's going on - another thing it has in common with "San Junipero." One thing that tickled me about this one's twist ending was the absolute triumph of parallel computing, or whatever the hell was going on there. So many Black Mirror episodes have played with the idea of time dilation in a digital world, where what feels like one second to us might be a thousand lifetimes to a sentient piece of code. Here, that's played backward, almost, and the months-to-years-long story we've been watching turns out to be just one in a thousand simultaneous intricate simulations in the near future's best Tinder-like algorithm that decides, instantly, how compatible two people are. The twist is, sure, a bit corny, and some of the details of the episode begin to fall apart after a brief retrospection, but I still loved this episode and loved its ending - perhaps the sole truly happy ending of any Black Mirror episode. (There's a dark, dark reading of the "San Junipero" epsidoe that I sort of half-subscribe to. We can talk offline if you're interested...)
Metalhead
I was skeptical when I heard the new season would feature a black and white episode, but goddamn was this a beauty. Good call, director David Slade! This is spare and simple, and reminded me a great deal of "White Bear" not only for its penultimate placement in the season but for its stark and harrowing story. In a vague post-apocalyptic world, a few human survivors try to eke out a living without being hunted down and killed by the "dogs," a bunch of drone robots equipped to kill any human on sight. This was better than, like, the entirety of The Walking Dead combined, and I'll never look at those Boston Dynamics robo-dogs the same way again. Holy hell, no!
Black Museum
Much like "White Christmas" before it, this is an anthology episode in its own right, laying out a smattering of somewhat connected vignettes before tying them all together with a neat little bow at the end. Among other issues, here, again, is the idea of digital "people," or sentient code, and this episode goes as far as to lampoon the idea of the ACLU dictating that code snippets have certain rights, too. For me, this episode was fine - just fine, really. A lot of cool ideas flying around, but not really a very memorable episode linking them all together.
And that's Season 4! It was worth the wait. Here's hoping there's a fifth season - but also, after churning out twelve episodes in fifteen months or so, I'd be okay with Black Mirror dialing back a bit and making sure it really has something new to say or explore next time it comes back. I mean, the idea is fascinating, but "sentient code" philosophy is such a far cry from the speculative fiction this show used to, and still can, excel so well at.