I have watched probably 50 of these various style of foreign noir series. Everything from The Bridge, Penoza, Trapped to Spiral (Engrenages}. Some are obviously much better than others; some are awful in spite of their inexplicable popularity. And some of the best ones fell though the cracks, like "Arne Dahl"; which I accidentally stumbled upon on an obscure review site.
They sure don't make 'em like they used to. I've had to lower my standards.
If you enjoy those types of shows than this series fits into the "worth a watch" bundle. Watchable, but it's not on the same par with Engrenages, that's for sure.
It looks and feels like a copycat of Spiral (Engrenages) to me. But, the special FX are almost distractedly bad for a modern show, sort of unintentionally funny. But the story line is good, and most of the cast plays their roles very well.
My only real problem with the show is the "soap opera" production style. it has a bit of the "General Hospital" kind of vibe. Dramatic pauses, over dressed, freshly painted stage-looking sets, overly choreographed and sorta overacted.
Some of the details are just plain stupid. For example: If a woman has been in a solitary confinement prison cell for 25 years, why is her hair and makeup absolutely perfect? She looks like an executive that just stepped out of a corporate boardroom. Her prison cell is nicer than some luxury hotels I've stayed in. That almost killed it for me in the first 15 minutes of episode #1.
In spite of all this, I have to admit that it kept me watching. I'm not finished with the whole series, but thought I'd chime in with an opinion.