Isn’t it odd the way we can start watching a streamer in absolute disgusted disbelief only to discover that we’re not only hooked but we’re scintillated by the very things that just looked like bad taste before? Isn’t that the way people had to grow into Slow Horses with all of Gary Oldman’s vaunted farting and abusing his team of assistants as the scum of the earth? It helped that they were a very wild and wooly team and that they could lose partners or suffer horrible loss. Ho, the technology expert, thinks he’s a god at one point (which is diverting and mad). It also helps that Oldman’s Jackson Lamb enjoys the loyalty of Saskia Reeves, never mind that she once ‘drank for England’. It’s good too that the Second Desk at MI5 is occupied by shrewd posh Kristin Scott-Thomas who’s come a long way since The English Patient. Well, we’ve just finished Slow Horses years after we felt superior and decided against it.

Just at the moment we’re riveted by Down Cemetery Road, also on Apple TV. The title is from Larkin (‘Give me your arm, old toad/Help me down Cemetery Road’) and the script is from a novel by Mick Herron, the master of mayhem of the Slow Horses books. It features two of Britain’s very finest actors Emma Thompson and Ruth Wilson. Wilson is obsessed by finding a child she believes is being held against her will. She is frustrated in her endeavours by a group of hideous-looking bearded men and is at some stage told by one of them that he is going to kill her, now.

All of this is enacted with a perfervid Absurdism that makes the wit wilt like summer flowers. Wilson is given to climbing to the top of a high Oxford building and feeling the terror of her proximity. But other things are afoot: she has gone to see the private investigator husband of Thompson about the missing/perhaps imprisoned child but he – a good, unworldly man – is soon murdered.

Emma Thompson, also a P.I., sports a hair cut like bird’s feathers and she’s shot to look as tall as she can. It’s a raffish alternative performance and she acts like an angel, a very final, Londony, archangel.

I mention these steep uncanny mutations of the populaire because the hero of Slow Horses (or at any rate the juvenile lead, River Cartwright) Jack Lowden is about to embark on a dramatisation of one of the most formidable crime sagas ever conceived. He is going to play Philip Kerr’s Bernie Gunther – detective for Weimar, detective for the Nazis – in Kerr’s comprehensive multi-volume crime epic. Philip Kerr always said he’d write a prequel to the sequence and in 2019, the year after he died, Metropolis was published and it indicated with a moody and brilliant shimmer of colour what life was like in the unbuttoned world which we associate with Cabaret, with Döblin’s Berlin Alexanderplatz, Christopher Isherwood’s Goodbye to Berlin and Josef von Sternberg’s The Blue Angel with Marlene Dietrich. There are images of Lotte Lenya doing Brecht’s The Threepenny Opera at Max Reinhardt’s theatre and the appearance of Emil Jannings, the great actor who depicts his torture at the hands of Dietrich. And we note the fact that Georg Grosz is a neat symbolic figure to appear given his appetite to capture the grotesquerie too behind the glamour.

Philip Kerr in this last prospective novel emphasises that this world where prostitutes can actually be scalped is a nightmare. If the world had listened to Keynes, Germany would not have been a jungle under such a play of lights. Of course, the decision to turn Metropolis and its fellows into such a highly organised pyramid in honour of crime and deduction has its own risks because it transfigures the horror in a ‘Tomorrow Belongs to Me’ way.

Hugo Boss designed the SS costumes and there will always be a Night of the Generals aspect to the glamour of the horror that Bernie Gunther disinters. In the first book in the Third Reich series, March Violets, he meets Goering, the ‘charming’ Nazi recently impersonated by Russell Crowe in Nuremburg. It will be interesting to see what image of life as a private eye gets from the great air ace who gave shape to the Gestapo, not just the Luftwaffe.

Will the TV streamer bring the terror alive along with the magnetism? It’s almost transgressive to allow too much humanity in – and some people think Nuremberg pulls its punches: Kerr has Goering with his hard, blue, intelligent eyes, quoting Goethe, dangerous as a tiger.

Jack Lowden will be tested in this series full of shadows and spiders. Philip Hensher said Slow Horses showed the influence of Shakespeare’s Henry IV – but this cuts both ways because the espionage genius is also – isn’t he? – the Falstaff figure.

Everything is allowed to happen in the Bernie Gunther stories. In The Other Side of Silence, the war over, Gunther tries to kill himself but then takes a job sleuthing for Somerset Maugham. Jack Lowden will need to be crisp, not just casual. He is the straightest character in Slow Horses – think of his scenes with Jonathan Pryce. In the TV streamer he will be acting with Colin Firth who inhabits the crispness and the style of the period.

Sometimes the books can seem a bit much. (Do we need Himmler obsessed with witchcraft? Do we need Eichmann and Goebbels?) There’s the banality of evil, sure, but do we need such layers of mystery and improbability?

What an ambitious medley of horror and pain underlies the Bernie Gunther series like an hommage to the le Carré universe of credible fiction in the assemblage of romance. But Kerr needs his hero and Jack Lowden – who has in his time done Ghosts and Chariots of Fire on stage – is superbly equipped to play him.

In the Times, Max Hastings and William Boyd nominate a collection of the best second world war books. All I remember, from Hastings’ list, I think, are The Young Lions (he warns against the film) and The Cruel Sea (there is a photo of Jack Hawkins, the Captain with the young Donald Sinden). I remember The Cruel Sea because I was thrilled to read it as a child. I remember The Young Lions – with its cover pics of Marlon Brando and Dean Martin – because my mother read it in hospital, a second time, because she was having a baby.