Ignore all the hater reviews, I for one, absolutely loved it. It was different from your usual BBC dramas that are trying to tick boxes and cover all the political issues we are faced with in the world right now. I have no idea why the 1 star reviewers, watched all 6 episodes. If I'm not engaged in a drama / series, you'd be lucky to get my attention past the first 15 minutes of episode 1.
It was easy to follow and didn't do that thing where is goes back in time and off plot. It was just an easy to watch gripping drama, as apposed to one where you have to try and analyse, to understand 'who dunnit'