Of all the Sherlock Holmes stories, Hound of the Baskervilles was always likely to need the most tweaking to turn it into a believable modern day yarn.
That the end result was so staggeringly good is a testament to the genius of show creators Mark Gatiss and Steven Moffat.
Casting Being Human’s Russell Tovey as a man who thinks he’s seen a large dog-like creature was a bit cheeky, but did you spot these other casting connections in tonight’s episode?
Playing barkeeper Gary was Gordon Kennedy who played Little John in BBC One’s lamentably bad Robin Hood.
In the far superior Robin of Sherwood, Little John was played Clive Mantle (Dr Frankland) who also played Dr Mike in Casualty where Will Sharpe (Corporal Lyons) played geeky trainee Doctor Yuki Reid.