Despite having a frustratingly bland main plot, this episode of “Grantchester” also has some of the best material I can remember ever being on the show.

The episode picks up an indeterminate period from the previous; Al Weaver is awaiting his trial for “gross indecency” and spending his days—presumably unable to perform duties as curate—in his room getting drunk on vodka and listening to jazz. No one comments it’s like having James Norton back, but it’d have been amazing if someone did. I was actually waiting for it, but then it turns out Weaver’s a nasty drunk who’s mean to everyone, including Tessa Peake-Jones and Oliver Dimsdale. The episode will end up being about Weaver and Dimsdale and being a gay couple in fifties England, and it’s phenomenal stuff. It more than makes up for the clunky A-plot.

And while the A-plot is clunky—in the course of an investigation, Robson Green finds something out about Tom Brittney’s wealthy kid upbringing, and it seemingly breaks their friendship. The majority of the episode takes place one evening in the police station, where dipshit copper Bradley Hall hauls in some drunk U.S. airmen, and then there’s a mysterious death, and none of the airmen will give statements. Brittney’s only at the station because his step-sister, Emily Patrick, has been arrested for dine-and-dashing; they’d usually let a rich girl go, but she apparently knicked a valuable; only she won’t agree to a search, so she’s just hanging around Green’s office, verbally abusing the working class.

Including new office girl Melissa Johns, who’s been around since the second episode of the season and has been likable enough, but now she gets a bunch to do, and she’s excellent.

The rift between Brittney and Green doesn’t lead to any good acting together—it’s too sudden, too contrived, too forced into the restricted confines—but it does give Green, independently, some material. Brittney and Patrick, however, do get some good scenes together, with Patrick sort of establishing herself as a decent supporting “Grantchester” character by the end of the episode. Hopefully, she won’t be too regular. She’s rather unpleasant.

Another problem with the mystery plot, besides the sort of hackneyed story, is the acting. Ben Wiggins has a bunch to do as the American officer who bonds with fellow vet Green, only Wiggins isn’t any good. It’s vaguely rude to call him out for his Brit-playing-Yank abilities considering Corey Johnson, who is American, is also bad playing an American. But the other U.S. servicemen—particularly Victor Alli, who’s a Black man in a white man’s airforce stationed in a different white man’s country—are good. And they’re British actors. So whatever’s wrong with Wiggins, it’s not his inability to cross the pond in his performance. And with him being so milquetoast, the whole plot crumbles.

It doesn’t matter, of course, because everything at the station is just busywork between Weaver and Dimsdale scenes. The acting from Dimsdale is particularly phenomenal.

Louise Ironside’s got the script credit—British shows I think really do just credit the actual writer—and while her mystery isn’t great, her narrative construction and character drama are aces. And it’s not her fault they miscast.

The great stuff here is enough to make for a genuinely spectacular episode… even accounting for the gross missteps in casting and plotting.

This episode succeeds in ratcheting up Al Weaver’s arc to an almost intolerable point. The cliffhanger is less shocking than the last couple of episodes. Despite being abbreviated, it actually relieves some stress in its rush. Things go from bad to worse, as a boulder of fifties bigotry strikes almost everyone in the main cast. Including people outside the vicarage like Kacey Ainsworth, who finds herself again at an impasse with Robson Green on his apparent two-facedness with the “gross indecency” law. They’re basically couples friends with Weaver and Oliver Dimsdale now, after all. There’s some profound subtext in the dialogue about Green and Ainsworth’s marriage, mainly how he can negotiate being a police officer when he doesn’t believe in the laws. It’s a nice character development scene and informs Green’s frustration with Tom Brittney later on.

Because it’s going to be up to Brittney to either lie for Weaver or exonerate him through lying. Everyone else has been in for questioning, including Tessa Peake-Jones, who has her own arc about the investigation and comes out a lot more sympathetic than initially implied. Green’s dipshit cop sidekick, Bradley Hall, is really gung ho to prosecute Weaver—and out Dimsdale too if he can—and there’s only so much Green can do to steer the interviews out of Hall’s grasp. It’s going to be up to Brittney. The episode reminds the audience every five to ten minutes.

So then the murder plot—it feels almost strange to call it the A plot, though this one does take up more of the episode because the B plot figures into both it and the Weaver plot. The murder plot involves the local town council election; tragically widowed Rebecca Front against scheming bigot entrepreneur Will Hislop (who’s so villainous he should worry about getting typecast). Front’s husband was on the town council for years and then suddenly killed himself. Front’s trying to get his chair. Hislop and cousin Orlando Wells are out to take it back for the right kind of Briton.

There’s a bit about Front as an assertive woman in the fifties, but it ends up overshadowed thanks to her pal, Jonathan Aris. Aris is a novelist in town to help her in her mourning and maybe research a new book. His interests intersect with Brittney and Green’s, so he’s around a lot. Front’s around at the beginning of the episode, but then a lot less. There are more than a few scenes where she’s used as scenery, figuratively passed between characters to get a reaction. Richard Cookson’s got the script credit; there are some really thin stretches of the plot, particularly with the murder mystery. All of the attention goes to Weaver’s arc, which Brittney unwittingly drags into the political story.

Lots of good acting. Weaver, Peake-Jones, Brittney gets in a couple terrific scenes. Gary Beadle’s back as the bigot Archdeacon. Aris could be better. There’s just something insubstantial about his performance like he and Front don’t really click as good friends; plus, he always seems like he’s going to rip off his mustache for a Scooby-Doo reveal.

But who cares about the mystery arc when the character drama stuff is so much better. “Grantchester”’s relentless this season.