Although it's a period drama set in the dim and shadowy London of 1956, The Hour can’t help reminding us that the more things change, the more inclined they feel to do a brisk U-turn and fly back to hit us in the teeth.

Just as we thought we were getting tired of the format, the BBC rang in the changes. It was no longer an apprentice Lord Sugar was after, but a partner in a business that he would invest a quarter of a million in. The candidates – 16 freshly laundered suits kicked us off – did the usual strutting and rustling of peacock feathers (a large part of the programme’s success is surely due to these cringeworthy failures of self-insight). But still, this year things seemed a little subdued on the bravado/bullshit front – though Northern Ireland Jim, a cliché machine, yes, but an impressively persuasive one, gave it his best shot.

Who could argue that television isn’t a great medium for learning about art? In its pared-down, visually literate way it delivers what dull, theory-laden extrapolations often can’t (if only because artists don’t think that way when they make things, and we don’t think that way when we look at things). It can breathe renewed life and vigour into a subject we think we know well, and, as a medium for simplified, pocket-sized information, it can get straight to the heart of a matter. Perfect. Possibly. And so we come to The Impressionists: Painting and Revolution.

If I'm being honest, I never saw the charm of Alan Bennett's Talking Heads. Too many quiet disappointments, too much capital-A Acting. They lacked naturalism in presentation and content, whereas Double Lesson, from Channel 4's First Cut series of quirky documentaries and quasi-documentaries, had naturalism to spare last night.

The return of Russell T Davies’s second most famous creation arrives coated with a transatlantic sheen, courtesy of an injection of co-production money from the USA’s Starz cable network (home of Spartacus and Camelot). Happily, this has not obliterated the homegrown roots of the Doctor Who spin-off, since this opener cut fearlessly between portentous action scenes at CIA headquarters and a judicial execution in Kentucky to Cardiff city centre and expanses of rugged Welsh coastline, where Gwen Cooper (Eve Myles) was trying to live an anonymous post-Torchwood existence with her husband and baby.

Programmes about Italian organised crime made by the foreign media are always hampered by the finnicky nature of the beast itself: there is so much background detail that needs to be staked out at the outset that your head is whirling from information overload. Like its mainstream political parties, high-street banks and national daily newspapers, Italy has three, four or five times as many of each as any other European country of similar size.

Sarah Waters’s highly praised novels have marched from the page to the screen with regimental regularity and no apparent sacrifice in quality. Tipping the Velvet and Fingersmith, with their big Victorian brushstrokes, were built for television no less than Dickens is. With The Night Watch, adapted last night, her subject was still the love that dare not speak its name. But two things were different. This time Waters’s sweeping saga was compressed into a single film.

Does James Fox fancy himself as the Niall Ferguson of art history? I ask because clearly this latest addition to the growing pantheon of television art historians wants to do for British art what Ferguson sought to do for the British Empire. He wants us to stop apologising, and to admit that we’re simply the best, better than all the rest. And though I grant you he is similarly photogenic (with a touch of that swarthy, swaggering arrogance, too) the ratio of plausible statement to incredulity (my own, whilst spluttering and tweeting my incredulity) was considerably weighted towards the latter.

The leap from BBC Four to Channel 4 is more than the flick of a switch. Migrating from the BBC’s digital channel to its terrestrial broadcast has transformed the Danish noir drama Forbrydelsen. It's now in English. It’s become American. Copenhagen has been banished. The alchemist responsible is US TV network AMC. Channel 4’s screening of the US remake of The Killing will attract more viewers than BBC Four ever could, but it’s impossible to watch the Seattle-set makeover without thinking back to the original

What a strange, shape-shifting thing Luther is. Storylines ebb and flow around Idris Elba's dauntingly huge central character like flotsam and debris borne along on a heaving swell, but the man himself wades imperiously through it all like the Colossus in an old Jason and the Argonauts movie. Gross professional misconduct, subterfuge and blatantly aiding and abetting criminal behaviour are all part of Luther's daily routine. It's quite easy to forget that he's supposed to be a copper.