A caption at the start informs us that we're in England in 1327. Queen Isabella (Aure Atika) has just defeated her husband, Edward II, in a brutal civil war, thrown him in prison and installed her son, Edward III (Blake Ritson), on the throne.
When Edward II mysteriously expires, rumours that he's been murdered abound.
Watchful nun Mother Cecelia (Amanda Richardson, one of many familiar faces floating around the place) fuels the gossip by suggesting the deposed monarch died "with a red hot poker up his arse".
There's plenty of salty language like that in World Without End, along with a lot of violence and gore, a smattering of sex and more than a few whiffs of incest, among both the high- and low-born. It's basically a kind of 14th century EastEnders with the fictional town of Kingsbridge in place of Albert Square (there's even a marketplace). Into this milieu wanders wounded knight Sir Thomas Langley (Ben Chaplin), who's just about survived a swordfight with two of the Queen's soldiers.
He takes refuge with Mother Cecelia and announces he wants to become a monk. He's treated by local healer Mattie (Indira Varma), who's has taken on the central heroine, the fragrant young Caris (Charlotte Riley), as her apprentice.
But Mattie ends up being hanged as a witch and poor Sir Thomas falls prey to the less tender ministrations of mad Brother Joseph (a hilariously over-the-top David Bradley), who hacks off his infected arm with a meat cleaver. Amputation, bleeding and dung poultices are Brother Joseph's solution to every ailment.
To be honest, I hadn't a clue half the time what was going on here. The great Peter Firth, late of Spooks, struts around as Sir Roland, snarling and hanging people willy-nilly (the climax of the episode is a mass hanging on a collapsing bridge).
Sex and the City's Cynthia Nixon, giving a performance that's 10pc acting and 90pc smirking, is the ambitious Petranilla, who murders her brother-in-law with poison mushrooms and, during the bridge collapse, drowns the abbot so her wimpy son Godwyn (Rupert Evans) can take his job.
I'm sure it will all make some sense eventually. But life is too short to waste on such preposterous baloney.
There's plenty that's preposterous about Ripper Street and a lot that's highly enjoyable, too: Matthew Macfadyen's sturdy performance as ahead-of-his-time cop DCI Reid (a real-life figure, incidentally), the atmospheric recreation of Victorian London (shot entirely in Dublin) and, of course, the abundance of bodily fluids.
This week Ripper Street was awash, not with blood, but with vomit as the citizens succumbed to what appeared to be an outbreak of cholera, but which turned out to be a dastardly plot by a deranged baker to poison the populace with toxic flour.
Ripper Street has reportedly been causing faint-hearted BBC1 viewers who prefer their Sunday night drama to be Call the Midwife-strength to choke on their cocoa. That's fine by me.
In the latest series At Your Service, the Brennan brothers, Francis and John, advised the owners of Hayden's Hotel in Ballinasloe that more weddings were the answer to their problems.
The best advice would probably have been, "Give it up, lads." The makers of At Your Service, which looks desperately jaded, would do well to heed it themselves.
World Without End 1/5
Ripper Street 3/5
At Your Service 1/5