Natalie Haynes: Here's the real reason why Sarah Lund is about to take over our lives again

The thing is that if you are planning on going out sometime during the next 10 Saturday evenings, you'll have to count me out. And while that may seem like a positive perk, you will also have to count out a large percentage of other people, even ones you like. Because the second series of the Danish thriller The Killing returns to BBC4 this Saturday, and many of us will be manufacturing excuses like Olympic-calibre liars in order to avoid missing an episode.

The first series of The Killing was that most elusive televisual holy grail: water-cooler TV. Everyone, it seemed, was watching it and talking about it, even though it was in Danish and the whole cast wore thick jumpers. In fact, the jumpers became one of the show's main selling points: Sarah Lund must be one of the least likely fashion icons of this century, and she didn't even have to wear a meat dress to do it.

The Killing was the opposite of the average crime drama. Instead of solving one or more murders in an hour-long episode, they went for one murder and solved it over 20 hour-long episodes. It felt more like a novel than a TV show, albeit a novel with 19 cliff-hangers.

It was also – unusually for a detective series – prepared to show pain. Most murder victims in the TV world are little more than plot points. When Poirot or DCI Barnaby turn up to investigate a murder, they aren't greeted with a cast of demolished, wounded people. The victim was annoying and unloved, so that we can better believe that any one of the suspects did the deed.

The Killing shows the agony of murder, and not just for the victim and their loved ones. They revel in the damage caused by a murder investigation: of the harm done to the suspects, the witnesses and the detectives. And because of this hyper-real sense of tragedy, viewers felt that if the worst happened to them, or someone they cared about, they wanted Sarah Lund to investigate.

Like Columbo before her (though with admittedly fewer cases where the murder weapon is a pair of Dobermans and the word "Rosebud"), Lund is preternaturally observant and persistent. She commits to solving the crime at any cost to her personal life or her popularity. She isn't a genius, like Sherlock Holmes, she's simply better at understanding crime scenes and motives than anyone else, and she will give up the day hell freezes as hard as a Danish winter.

In other words, she is a heroine for our times: she may be a bad mother, daughter and girlfriend, but she brings certainty back into uncertain times.

www.nataliehaynes.com