I agree with a PP that the writing of this series was terrible.
And for the 2 lead characters, who happen to be women, were really let down. They were insubstantial, and virtually irrelevant.
And even though previously I thought it was as though they wanted to give Billy a much larger part as obviously we wont be seeing him again, it shouldn't have been at the expense of other characters.
I just about followed all the twists and turns until the actual killer was revealed, but apart from the fact that he had already been shown to be not very nice, why all that ritual nonsense with the ropes. And why would she just go along with it.
I think all of that theatrics actually went against it working as a plot it left you thinking why would Arthur Mair be someone who would indulge in them.
I suspect Ed is a sort of Duncan replacement, which is why it is so disappointing that the idiot writer made him and Ruth pair up. Even allowing for the shallow characterisation I think Ruth starting to challenge him was because she realised she was trapped. And he seemed to shape shift from weedy just getting by to be some sort of assertive macho bully.
But the fact that he sat by and did nothing to help (forgotten his name) the young man Ruth had press ganged into being an informer is the biggest mark against him being a remaining character.
Just hope as they have confirmed another series that they get rid of the writer of this series and that there is a better balance in terms of character development and back story for both Ruth and Tosh.
They were just left with 2 dimensional scenes.
(And no Sandy was NOT overacting. He always gets a bit carried away when put in a position of responsibililty!)