Well, he's the hero of BBC1's new crime drama starring Kenneth Branagh (9pm tomorrow BBC1). But what shaped this melancholic Swedish detective, and why have more than 25 million copies of the novels featuring him been sold worldwide? Crime writer John Harvey travels to Sweden to find out, talking to people on the streets, shadowing a cop and tracking down Wallander's reclusive but lucid creator, Henning Mankell. By examining Mankell's anti-hero Wallander, it reveals the hidden angst affecting present-day Sweden, a country with an excellent welfare system yet one which has suffered two shocking recent political assassinations. The film tries to grasp what Mankell's characters say about Sweden and how his books inform the rest of the world about Scandinavia's largest country.