Probably one of best crime thriller series. What's unique about this series is it's not about a single case or related cases. It's about the psychology of criminals, specifically serial killers. So it'll not hook you up with a single or multiple related cases and ends with solving the cases, rather than there's multiple cases one after another, and sometimes there's not even a case. There's just talking with serial killers and looking into their minds. Why do they did those things, what was going through their minds when they murdered those people and various other aspects of their minds. And that makes this show a masterpiece. You don't know where this show is going, how it'll end, who are the main characters. You just enjoy every minute of the show. There's not a single episode or a single minute which is boring. If you're looking for a crime thriller, you should watch it.