I found Episode 2 quite intense and scary.......I thought the story was perhaps the best of the episodes I have seen, to date.......I have not seen the other productions of the story. I loved how the writers updated it.
I have always loved 'The Hound of the Baskervilles' and thought this rendition, 'The Hounds of Baskerville' was very different indeed but quite refreshing. Not my favourite of three from series 2 because of the differences between this and the Basil Rathbone / Nigel Bruce original movie, but all the same a great episode.
What confused me was the very short shot at the end of the episode that showed Moriarty. I don't recall his role in the original story. Did he have a hand in creating the situation that Sherlock found himself in?
I can't quite remember I would have to watch it again. His release from a prison cell sets the story up for the last episode of series 2, which I thought was the best of the three with Moriarty on fine form. I can't give anything away if others are interesting watching it.