Now that JC has aired and the "reviews" are in, here's what I think about it.
I agree with posters who say it wasn't as good as it used to be. My bugbear was that Alan Davis looked cheesed off anyway. The solution of the mystery being revealed at the offset was unusual but because of the idiot Ridley it was done like that so we could realise just how imbecilic he was. I would have preferred the Ridley character to not to have been included however. I liked the way Creek was still thinking about the tiny things like the upside down picture and there were really great comedic lines. "Why is everything so hard?" "Probably the rigor mortis".
The dynamic of Creek being married and moving on was set up in the Easter Special last year, but was not really explored until last night, because in the special he had his sidekick Joey with him to help him investigate. Of course the episode could have been better. That isn't in dispute, but it also could have been a whole lot worse. It was really funny when JC's wife was explaining the "disappearing ashes" mystery and straight away JC said "robot vacuum cleaner". This episode, whilst not delving into the realms and depths of magic and mayhem, demonstrated that even as JC was getting older and the "younger generation try and take over" (said by JC himself), that the quick thinking and problem solving was still what drove JC and what he got off on. The elements were there of a great mystery, but I do concede that it was the reveal of the mystery prior to JC's investigation that people were disappointed in.
It was on the whole, an enjoyable hour of telly, and even though the programme peaked back in 2001 with Satan's Chimney, i did mostly enjoy the episode. The quick witted one liners still demonstrated that writers like Renwick are rare and as there are only two episodes left, I will gladly watch them and enjoy them, even if they are slightly less conceived and delivered compared to what came before.