Excellent.
Adler-Olsen is a Danish crime fiction writer best known for his Department Q series.
The first book in the series is The Keeper of Lost Causes. (2013)
Carl Mørck used to be one of Denmark’s best homicide detectives. Then a hail of bullets destroyed the lives of two fellow cops, and Carl—who didn’t draw his weapon—blames himself.
So a promotion is the last thing he expects. But Department Q is a department of one, and Carl’s got only a stack of cold cases for company.
His colleagues snicker, but Carl may have the last laugh, because one file keeps nagging at him: a liberal politician vanished five years earlier and is presumed dead. But she isn’t dead…yet.
I particularly enjoyed Mørck’s sidekick, Assad.

It was adapted in a 2013 Danish film.
Click PLAY or watch it on YouTube.