Season 4’s worst episode is also its most scattered: A young woman visits a macabre roadside museum, where the weirdo curator tells her the origin stories behind three of his “criminological artifacts” — so it’s like an anthology within an anthology? It feels like a collection of half-baked tales that weren’t strong enough to merit their own episodes, and the tone is much more ghoulish and sadistic than usual. A (fairly predictable) final twist isn’t enough to redeem this one, which now sits among the most skippable Black Mirror episodes ever. Grade: D-plus
5. “Metalhead”
Black Mirror occasionally drops any pretense of high-minded sci-fi and goes for straight-up horror, as it does here with this spare tale of man vs. machine, told in stark black-and-white. Maxine Peake plays a haunted survivor being chased by a murderous robot guard dog through a barren, post-apocalyptic wasteland. It’s a lean and mean story, without much dialogue, and it’s certainly a nail-biter. But we never learn enough about the woman to care very much whether she survives or not, and the conclusion is almost too grim to stomach… especially around the holidays. Grade: C-minus
4. “Crocodile”
Oh, it’s dark you’re looking for? Try this supremely depressing tale of a famous architect (Andrea Riseborough) whose heinous past crimes might be unearthed by a plucky young insurance investigator (Kiran Sonia Sawar) and her device that can read people’s memories. This one takes a while to get going… and when it does, it becomes almost unbearably bleak. The courage to go so, so dark is admirable, and Riseborough and Sawar both rise to the occasion, but this one is ultimately too bitter a pill to swallow. Worth watching, though, just to gawk at the automated pizza delivery trucks. (I want one!) Grade: C-plus
3. “Arkangel”
Alternate title: “A Mother’s Worst Nightmare.” Rosemarie DeWitt stars as an overprotective mom who agrees to have a chip inserted in her young daughter’s skull that tracks her location, monitors her nutrition… and even allows the mom to see through her daughter’s eyes and blurs out any objectionable content the girl might see. It works fine for a while — but when the girl grows into a teenager and starts rebelling, things go very, very badly. Director Jodie Foster crafts a tense and eerie tale that raises fascinating questions about the limits of good parenting, and Witt is flat-out terrific in a demanding, not-always-sympathetic role. Grade: B-plus
2. “USS Callister”
What starts off looking like a straight Star Trek spoof takes about two or three sharp turns along the way. Jesse Plemons plays a nerdy recluse who runs a virtual-reality gaming company and spends his nights recreating his favorite old sci-fi TV show, casting himself as the heroic starship captain. But! His virtual starship is actually a prison where he traps clones of his hated co-workers and forces them to play along with his fantasies. It’s a wickedly ingenious twist, and the cast of familiar faces is superb — especially Cristin Milioti, as a new hire who gets sucked into her boss’ game and fights to find a way out. By the time the story circled all the way back around to become an earnest sci-fi adventure again, I was fully onboard. Grade: A-minus
1. “Hang the DJ”
Like the very best Black Mirror episodes — “San Junipero,” “Be Right Back” — “Hang the DJ” is soaringly romantic, with two young lovers (Georgina Campbell and Joe Cole) stuck in an immersive online dating system that dictates who they can date, and for how long… down to the minutes and seconds. The two are split up too soon, but keep finding a way back to each other; it’s a tale of true love, forced apart by emotionless algorithms. (Their digital assistants keep insisting that “everything happens for a reason,” though.) Campbell is a star in the making, there’s sly humor throughout about the absurdity of automated matchmaking and the story builds to a beautifully touching finish. If you only watch one Black Mirror this season? Make it this one. Grade: A