The South Bank Show, Sky Arts 1 /Sebastian Bergman, BBC Four

Lord Bragg permitted himself a knowing chuckle as he introduced Sky Arts's resurrection of The South Bank Show from the South Bank. He was standing in front of the National Theatre, whose director Nicholas Hytner was this week's subject, though within seconds he had been teleported to the streets of Manhattan, to preview the opening of Hytner's production of One Man, Two Guvnors on Broadway.

The message, from both Bragg and Hytner, was that the arts are vital, they can be massively popular, and they cross frontiers both imaginative and physical.

Director Suzannah Wander had delivered a hugely enjoyable film, peppered with splashes of guest stardom and illuminated by extracts from Hytner's amazing streak of greatest hits, among them Miss Saigon, The History Boys, The Madness of King George and War Horse. Hytner himself, making his debut as the subject of a TV documentary, made a lucid and coherent narrator of his own story, as well as an inexhaustible fount of ringing soundbites. Theatre is "an essential weapon in the campaign to know ourselves better," he averred. What's more, "great theatre, high and low, is an essential part of the cultural conversation." As for the world of directing, "the ones who make it are the ones who know how little they know."

We can take it for granted that Hytner knows a great deal, and his quiet, contained manner makes him an attractive subject, but you know there has to be a bit of the fire-breathing tyrant in there somewhere. There was a hint of this in James Corden's account of how Hytner had called a dramatic halt to rehearsals for One Man, Two Guvnors, and delivered a broadside about the perils of the cast laughing cosily at their own jokes.

Hytner himself offered a glimpse of the stern taskmaster within while talking about his experiences as an opera director (a job at which he claims not to rate himself highly). He felt his approach to opera had become "timid", he said, adding that "measured good taste is the last thing that opera needs." Somebody, somewhere knows that this means them. But Hytner will doubtless appreciate Alan Bennett's compliment: "Directors are very often stars of their own productions. Nick isn't like that."

For those of us still lamenting the end of The Bridge, our chums from the frozen north have supplied a short-term palliative in the baggy and unfit shape of Sebastian Bergman. Played by Rolf Lassgard (legendary in Sweden for his portrayal of Wallander) like a vagrant who's been kicked out of a care home for molesting the nurses, Bergman fits an increasingly familiar template of the anti-social anti-hero. He's the most instinctively brilliant police profiler of his generation, but his morbid disposition, list of personal hang-ups and perpetually offensive behaviour mean that his colleagues would rather change careers than work with him again.

Also, though he resembles a sack of rubbish waiting to be carted off by the recycling truck, we're asked to believe that he enjoys implausible levels of success with women, though this may be because he tries it on with any female within a half-mile radius. His excuse is that his wife and daughter were drowned in the 2004 tsunami, and he's tormented by a recurring nightmare of losing hold of his daughter's hand in the surging flood.

Inevitably, the Swedish cops find themselves putting up with him anyway, as Bergman elbows his way back into the investigation of the killing of a teenaged boy. It just happens to be taking place near the home of Bergman's recently deceased mother, and gruff police chief Torkel Hoglund (Tomas Laustiola, pictured above left with Lassgard) can't help feeling a twinge of sympathy for the rather pitiful Bergman. The history of professionally incestuous relationships within the police department doubtless plays its part.

This was a self-contained 90 minute story, so the solution and denouement seemed to arrive with indecent suddenness. The old routine of setting up almost every character as the potential killer is looking very long in the tooth, but the ensemble performances were strong, the baleful horn music was aptly melancholic, and those slate-grey Nordic skies are starting to feel strangely comforting.