The six new episodes of the show have a unifying theme (with the exception of “Metalhead,” a tense, maddening thriller shot in black and white that’s the shortest episode of the bunch at 42 minutes). They’re concerned with digital consciousness—what it means to connect our brains directly to the cloud. “Crocodile” explores the ramifications of this in a similar fashion to the first-season episode “The Entire History of You.” “Arkangel” imagines a new technology that affords parents greater insight into what their kids are experiencing. Other episodes consider a phenomenon the show has mulled before: the ability to copy a human soul, turning cloned consciousnesses into digital slaves. Our Siris, our selves.

What can it mean, this sudden coalescence of disparate dystopian concerns into a single form? In execution, the fourth series is remarkably patchy, even with the abundance of resources and talent that arrived with Black Mirror’s move (after its second season) from the British network Channel 4 to Netflix. As a body of work it’s more interesting than satisfying, although “USS Callister,” the standout episode, is spectacular, while “Hang the DJ” has the kind of winning optimism that made Season 3’s Emmy-winning “San Junipero” such a hit. The cast and crew involved this time around range from Jodie Foster (who directed “Arkangel”) to Jesse Plemons to Andrea Riseborough to David Slade. But the problem now is the writing. Some episodes (“Crocodile”) sacrifice plausibility and character development for tenuous moralizing that ultimately makes no sense. Others (“Arkangel”) are predictable at best and sometimes tediously bleak.

It’s not uncommon for Black Mirror episodes to feel like they begin and end with a clever idea—something that starts as a neat trick or a devious twist but fails to go much further. Season 3’s “Playtest,” which used the generic framework of horror to imagine the potential disaster of an immersive video game, never found its way beyond anything more than a concept, ending with a clunky thud. “Black Museum,” the final episode of the new season, doesn’t disappoint in its conclusion, but it takes such a roundabout way of getting there that you wonder what it’s all been in the service of. Without giving too much away, the narrative is an excuse to revisit Black Mirror’s greatest hits, via a grisly museum in a rural southwestern corner of America. The exhibits are artifacts from notorious crimes of the recent past; most nod back to previous chapters of the show’s history.

The episode’s frame is a wink to audience members who love finding Easter eggs hidden in the show’s crevices (Season 3 employed hashtags and news items glimpsed on some characters’ devices to suggest that different episodes were coexisting on the same timeline). But it also feels like a missed opportunity. “Black Museum” is structured around three different stories told by a museum curator to a visiting tourist. As in the episode “White Christmas,” the different stories are all linked, and they converge at the end in surprising fashion. But it’s frustrating to see all these nods to previous stories when the show doesn’t ultimately dig into them. Why acknowledge that the Black Mirror universe exists at all if you’re not going to do anything with it to expand its cautionary vision?