As with all crime shows in sleepy villages/towns you wonder at the amount of villainy contained in the district. So when a girl appears to stab a taxi driver to death for a meagre amount of cash and then escapes police custody, at the same time as a man is found dead from a heart attack in the city square, the two events seem unrelated. But they do eventually tie together in a convoluted but not difficult to follow story with plenty of red herrings and clues. When the big reveal of the uber plot is shown it seems quite logical, having seen all the clues leading up to it but still comes as a surprise. And a bit of heartache.
Of course, good writing doesn't carry the story far without good acting, and here even the bit actors are excellent. The main actors are equally so, playing their characters to perfection - especially Branagh with his version of Wallander as a policeman who cares too much for the victims but is crap about caring for himself. With someone else you might not care but his Wallander is very real and very much the person you'd want to have solving your murder, but would you want to be his friend?