May be British shows are for a specific type of audience. I cant figure how they pick any genre and just transform it into a beautiful story with emotions and personalities. The focus for most shows is on how people think and do what they do. I have to say Unforgotten hits the right mark. Starting with the pilot, they showed a hint of each character - Simple and normal people you would meet everyday and end it by making them all people of interest in a 40 year old case. And how the show has developed since then with marvelous twists and turns, powerful performances and a real and beautiful London in the backdrop. I have reached only till the fourth episode as of now, and I have to say it is easily one of the best crime dramas I've ever seen.
Review of Unforgotten
