I was away for the weekend, HDed it, and just seen it.
The story was preposterous. There was a lot of plot which sagged.
What was the point in them being locked in the cellar? (Peeing on the cat food was a bit like the One Foot episode 'Hearts of Darkness' when Victor is attached to Mrs Warboys with cement and pees against the tree: 'Sorry Mrs Warboys, you're just going to have to look the other way and put your fingers in your ears!').
When we first see Sheridan Smith's character Joey Ross in this ep, and Jonathan ttells her he knows she's been working as a waitress because she has ink on her elbows as she's been leaning on the small ads etc seemed out of place, somehow. That sort of observation fits better coming from Patrick Jane in The Mentalist, or Monk or House, than this.
There was no mention of Paul McCann's brother until the 'reveal'. This information should always be set up, even if it's just in dialogue. McCann's character HAD to confess all about that, because Jonathan would never have got it because he didn't know he had a brother.
The sub-plot with Krauss was extraordinary weak. Just as bad as the 3D porn sub-plot he had last time. He's a good actor and a good character, but that part especially needs a good script. And when they were explaining the technology involved with the 'fixed' videos of Klaus it loses even more. I'm not even sure an amateur techie could do that without spending his Sundays at Pixar.
And McCann's character shouldn't have got away with it. That resolution has happened in a few crime things and it always leaves a bitter taste in the mouth.
Doreen Mantle (Mrs Warboys) didn't seem to do much. I was rather wondering if she would be the murderer - that she had made up that whole 100-year old story herself. She just seemed to be a steriotypical house keeper.
And Sheridan Smith's dialogue seemed to have been 'modernized'. All 'come again' and 'I was like' etc. A minor quibble, that, admittedly.
I think the main problem was: it wasn't a locked room mystery. The best Jonathan Creeks - and indeed practically the whole of Series 1-3 were locked room mysteries. They were contained and cosy. It worked. Or, it was a puzzle - like the fantastic 'Time Waits for Norman' episode.
I'm going to try and forget this one happened, really. If it's the last-ever episode, then it's a shame - but saying that, the Series 4 finale in '04 was worse, I think.