Thank goodness the earlier books in this series are now available, because understanding Hanne Wilhelmsen requires back story. Especially now as it's hard to avoid a sneaking suspicion that there's just a little bit of her in Saga Norén. Maybe only a little, but still bells are ringing.
A classic slow burning Scandinavian thriller with some balance between the personal and the professional, there is a lot of back story in DEAD JOKER. Which fans of this series may appreciate, whilst some readers might find it just creates a lot of pages. Personally, this reader loved the chance to fill in so much of what makes Wilhelmsen tick, where she struggles, and the colleagues she's closest to - including the wonderful Billy T. Everybody really needs a friend like Billy T, although he might sometimes wonder why he has a friend like Wilhelmsen.
The crimes and investigations at the centre of DEAD JOKER involve a couple of horrific, violent events, particularly in the case of Halvorsrud's wife, where he has been an enforced witness to his wife's awful death. For the longest time the investigation team struggles to find any connections between the two killings, or to explain how it is that their chief suspect has a very good alibi (any more on that would be way too much of a spoiler).
Combine the hefty personal components with some interesting sidelines into the workings of the Norwegian justice system and DEAD JOKER obviously isn't supposed to be a thriller, or a rapid, superficial read. All the book's in this series I've been fortunate enough to read thus far require commitment, and concentration. They aren't trying to be just entertaining, they are deep, introspective, thoughtful and often confrontational. They are built around real characters for whom life often goes pear-shaped (and that's not just the victims). And they are absolutely fascinating and worth every minute of your reading time.