Why had a region best known for Volvos, Abba and Ikea begun producing dark and violent thrillers filled with brooding detectives and avenging cyberpunks?

To find out, I headed to Norway and Sweden to meet some of the genre's best writers and deep thinkers.

Time - and resources - were tight. BBC Bristol's Time Shift strand has been churning out compelling programmes on a shoestring for nearly 10 years and I had just three days to film eight interviews in three cities.

First stop Oslo, where Norway's hottest property Jo Nesbø explained how he achieved the unlikely feat of turning the humble snowman into a symbol of bowel-quaking terror.

It was hard not to feel a tinge of envy for a man who'd only turned to crime writing because he was bored with the day job - which involved being the Bono-like front-man of one of Norway's biggest bands.

After a whirlwind filming tour of the city I took a flight to Stockholm where my colleague Naz and I went in search of the twilight world of Stieg Larsson's Millennium novels.

The next morning we talked politics with the urbane Håkan Nesser, a writer who drily questioned the current of left-wing angst that underpins so much Scandinavian crime writing, before another flight took us to the port of Ystad - Wallander country.

I hadn't expected it to be quite so twee, nor to see a tanned and refreshed Kurt lounging about in deck shoes, smoking a fag - but then actor Krister Henriksson only plays Wallander, despite the similarities he acknowledged in our interview.

The shoot ended, fittingly, with the woman who started it all - Maj Sjöwall.

In the 1960s, she and partner Per Wahlöö created a series of politically driven thrillers based around a long suffering detective called Martin Beck - books that would have a profound influence on Stieg Larsson and Henning Mankell.

"We wanted to change people's way of thinking," she smiled ruefully.

And that is the real story of Nordic Noir.

Robert Murphy is producer of Nordic Noir: The Story Of Scandinavian Crime Fiction.

The Time Shift strand continues with Italian Noir: The Story Of Italian Crime Fiction, also on BBC Four at 9.30pm on Monday, 27 December.

Comments made by writers on the TV blog are their own opinions and not necessarily those of the BBC.