It says something about the state of television that sooner or later every actor has to play a cop or a spy. Latest in line is Carey Mulligan, starring as DI Kip Glaspie in David Hare’s new four-parter Collateral.

McMafia has taught us to recognise one thing – you might call it the “Norton stride”. As the charismatic Alex Godman, James Norton has been advancing, confidently at screen centre, towards one challenge after another, and they have been coming (mildly put) from all sorts of unexpected quarters. He’s dealt with everything by pressing onwards, ignoring advice from all and sundry.

Happily, there’s hope for Spiral junkies – as series six ends, we bring you news that series seven has just gone into production. This is just as well, because these last dozen episodes have been an object lesson in how to make TV drama for the mind and body, nimbly evading cop show genre-pitfalls to bring us carefully-shaded characters operating within a Venn diagram of overlapping grey areas. Big kudos, yet again, to showrunner Anne Landois.

Despite horror’s omnipresence in cinema, British television has been somewhat deprived of jump scares. Every couple of years there’s an anomaly, such as Sky’s The Enfield Haunting or ITV’s Marchlands, but nothing has caught the public’s imagination – not since the innovative but controversial one-off Ghostwatch.

No doubt McMafia has its strengths, but it’s like a mug of Horlicks compared to the grappa-with-aviation-fuel blast of Gomorrah (Sky Atlantic). The Naples-set organised crime drama takes no prisoners. It gives no quarter, and expects none.

Talk about laughter in the dark. With every successive episode, the fourth series of Inside No 9 (BBC Two) has perceptibly turned a shade blacker. "Zanzibar" was a festive farce mashing up half the plots of Shakespeare from Macbeth to A Comedy of Errors. "Bernie Clifton’s Dressing Room" was a mournful reunion with a twist featuring a failed comedy double act. "Once Removed", told in reverse like Pinter’s Betrayal, featured a murder hit gone hilariously wrong.

Sara Lund and Saga Norén have a lot to answer for. Their adventures in the murk of murder as they grapple with their own dysfunctional psychology entranced audiences who don’t speak a scrap of Danish or Swedish. The search has since gone on for other gripping instances of Nordic noir. How long can it be before we accept that The Killing and The Bridge both had ingredients that aren’t easily reassembled?

What did the Romans do for us? On the evidence of new drama Britannia, they pillaged, murdered and tortured, but also found themselves mesmerised by the psychedelic Druid magic that hovered over our ancient land like fairy dust.

The new import is the latest procedural from Scandinavia, this time focusing on Stockholm’s biker gangs. The first episode aired Tuesday night, with the rest of the series available on All4 now.

“I’m black – I need to find out how black people live.” So reasoned Kiri, sitting in the back seat of the car driven by her social services case worker. She was on the way from her prospective adopters, a white middle-class couple who already had a teenage son, to pay a first unsupervised visit to her Nigerian-born grandparents. Kiri (Felicia Mukasa, pictured below) was mature beyond her years, open-minded and well-spoken, while her case worker Miriam (Sarah Lancashire) brimmed with mumsy good cheer and sensible advice.