Jørn Lier Horst, The Katharina Code (2017, Katharina-koden, translated by Anne Bruce, 2018)

So here we have a definite shift – the earlier Wisting novels came from small press Sandstone, but this book marks a move for Lier Horst to Penguin and the embracing of cliché du jour “figure walking away from us into snowy forest” book cover. The scene could be snowy, but the novel is set in October and not late enough that a fishing trip at a cabin isn’t practical. I note that Jørn Lier Horst’s name is smaller than the novel’s title, so he isn’t yet being sold on that.

This also marks the start of a tetralogy, The Cold Case Quartet, which might of course ease Wisting into retirement (he is in his mid-fifties by now?), and introduces not a new recurring character, but a new focal character.

So, we have a cold case: twenty-four years ago, Katharina Haugen vanished, leaving behind a packed suitcase and sheet of paper containing numbers and a cross. The world’s best cryptologists have tried and failed to decode the numbers and there is no sign of a body, let alone a culprit. Martin Haugen, her husband and legal widower, came under suspicion, but has been ruled out because he was too far away, working on a road construction project in Trøndelag. Every year, on the anniversary of her disappearance, Wisting and Haugen meet up, to reconsider the case, but this year Haugen is nowhere to be seen.

It seems obvious that Wisting is going to be trying to resolve this case, but it collides with another unsolved case: the kidnapping of Nadia Krogh, daughter of a millionaire, some two years before Katharina’s disappearance.

If we have a second case, we need Line Wisting, who is persuaded by someone from the new Cold Cases Group in Oslo, Adrian Stiller, to look into it. Not only is she encouraged to write a story, for the VG newspaper, but she is also persuaded to start a podcast.

We know Stiller, already, because he’s been to see Wisting, with the new evidence that has led to the reopening of the Krogh case: Martin Haugen’s fingerprints are on the ransom note sent to the Krogh family.

And so, Lier Horst weaves the two stories together, as Wisting has to be careful what he tells Line so as not to jeopardise his investigation and Line is not entirely clear how much she is being used by Stiller – she has met him in Oslo when he has been in Stavern. Line is, seemingly, an honest journalist, not given to tactical exposés, Wisting is an honest cop, sceptical of Stiller’s methods. But Wisting is having to lie to his daughter and, when Haugen reappears, he has to lie to him in hopes he can find a way to make him confess. Wisting has to go undercover to expose his friend – if, indeed, his friend is responsible for either of the disappearances.

We see a little more of Wisting’s interior this time and Line, curiously, only ever seems to drink water, rather than alcohol or coffee. Stiller, meanwhile, offers that new third viewpoint, with hints that he has a Deep Dark Secret that presumably we will take four books to get to. His chess playing is interesting – we’re not sure about his motivations and we are pretty sure he won’t stick to the rules.

Meanwhile, the old cases mean that the GPS and number plate recognition technology that has helped solve earlier cases (but not When It Grows Dark) is not available to Wisting, and cunning is needed, even as surveillance technology can offer a way into finding the solutions.