Shetland

They will bring in some sort of black go getter to meet diversity targets and beef up the story by his/her struggles to understand the local area. It'll be like a chilly 'Death in Paradise'.

I thought the plot was too convoluted and far-fetched in the end. Dougie Henshall is a fine actor and was convincing as a man going frayed at the edges. However, for me the characters have strayed too far from the original books. Sandy, for one, in the books is a clueless and even something of a liability, but here he was efficient and sensible. However, he at least did sound like a Shetlander.
As an antidote to the TV series, I am now re-reading the books, starting with Raven Black which is an intriguing psychological thriller. But those of you who only know Perez as Dougie Henshall may be disappointed!

I loved Mark Bonnar in "Guilt" as the dodgy criminal brother. I did wonder if Shetland would end with Perez leaving the island to set up home with him, because he said in the first episode he would never live there again when he left jail. I suppose that means he won't be in any new episodes.