Very very good Sci-fi, drama and police series in one nerve-wracking vintage.
A woman wakes up every night at exactly 03:33, in the middle of the so-called devil's hour between 03:00 and 04:00...
If you are not paying attention from the very beginning, yes, you will find it difficult to neither understand nor keep up. Be aware that the first episodes will be a bit messy, the story moves between different time frames, some characters come and go, situations change drastically and so on. Be patient though. It is an interesting, smart, entertaining. Exciting, nerve-wracking, slightly scary story and everything ties together in the end (as much as fiction can).
Actor Benjamin Chivers, who plays son Issac, the young son, is nothing short of incredible. The acting is exceptional from Peter Capaldi.
I covered all the episodes in one go, I couldn't stop watching.