Classic in Spanish productions that are not comedies: bad acting, poor scripts, extremely unrealistic depiction of police work and behavior, how university professors work, and so on.
The show pretends to be a formulaic thriller with the classic maverick detective against a mysterious serial killer (one of the few good points is to show the killer from the beginning).
The story is classic, but not really bad (in fact it is based on a novel) but the execution, in spite of the investment of resources, unusual for Spanish productions, is poor, because the terribly bad actors (the detective is the only that could be saved in this mess), the horrible script, poor action scenes and the plot holes.
Do not worth the time. Spanish producers should give up trying to emulate American noir or thriller productions, and, instead, to spent their effort in the comedy, the only genre in which they are proficient.