Detailed ratings: Non US users rating: 9.6. US users ratings: 3.6, so far.
The above is a very important piece of information, to make up your mind as to the actual quality of this series.
I've only watched the first episode so I'll make it short. I thought this dark BBC thriller was not only original, but extremely well filmed, suspenseful, realistic (real northern Irish actors and Gillian Anderson a word perfect English lady, in what clearly is Belfast itself), very well acted all round. It is not a whodunit, we're made to follow from the start both a MET detective and a serial killer's lives, as one tries to figure out, find and catch the other, and the other one fights his addiction to rape and kill on a daily basis. The tone is dark, the story is very chilling, but that's only because the protagonists are so very...ordinary. They could be us, any one of us.
It's nice to see a story set in Belfast that is NOT about the troubles, (even though there are - few - references and slang words only local to the north)
I really hope this carries on in the same vein throughout the next 4 episodes. While both series have nothing in common, it reminded me of that enthralling underrated gem Ultraviolet, another left-field BBC masterpiece that still has a dedicated following to this day.
10/10 for episode 1, can't think of anything yet to even give it a 9 to be honest.
Update episode 2, 10/10. Unexpected twists! Update episode 3: 10/10; Infinite shades of grey. Update episode 4: 10/10; I'm bolting my front door and double-checking all the windows. Update episode 5: 8/10. A slightly weaker link to the next season, which I can't wait for, now.
I must add a warning for sensitive people: There are a few graphic, realistic, upsetting scenes.