Generally speaking, I found this series to be pretty good, appreciating its subtle humor, well-developed characters, and a fairly intricate storyline. I’m not familiar with the National Treasure series, though I would certainly watch one starring Robbie Coltrane. I'm inclined to watch anything featuring Sarah Lancashire; she’s become someone I really like watching, particularly since she’s had opportunities to play a range of different parts after her time on Coronation Street as Raquel. Her performances in Happy Valley and Last Tango in Halifax were both excellent, among others. However, regarding Keri, I read one critique that claimed even Ms. Lancashire couldn't redeem the mini-series, which made me wonder what it needed saving from. My wife used to work as a social worker, so I’m often frustrated by how that profession is portrayed in films and television programs. This one seemed more reasonable than most, though. The characters involved in this child’s situation all face disapproval from viewers, and it seems like it's the character’s turn to be disliked. Many people were unhappy with how things concluded, and I can see why they felt that way; I did too. It just seemed unjust. I won’t go into details, but it appeared as if the writer considered different possible endings and then decided on one designed to provoke a reaction. I believe they made a poor choice because I don't find it entirely convincing, but it didn't significantly diminish my overall enjoyment of the series.

Source on TMDB