A Scandal in Belgravia kicked off Sherlock’s second series in fine style. Can the second episode, The Hounds Of Baskerville, not only live up to those high standards, but also the legacy of Arthur Conan Doyle’s most famous tale? The short answer is, yes.

Sherlock has gone cold turkey at the start of this week’s episode, desperate for a cigarette and a new case to solve. Work has dried up until a fragile young man called Henry Knight (Russell Tovey) approaches him with claims that a gigantic hound is on the loose in Dartmoor. He believes this beast was responsible for his father’s death some 20 years earlier. Sherlock is naturally sceptical, but eventually agrees to take the case on.

So Sherlock and John set off for the “bleak but beautiful” Dartmoor and, after meeting some of the locals, they end up infiltrating the Baskerville Army base, reported to be conducting unnatural experiments on animals. Could this hound be more than the mind playing tricks?

This is actually a very different episode from anything we’ve seen in the Sherlock so far. It takes the show firmly into psychological horror territory. Visually, it looks different too, thanks to the setting which pulls Sherlock out of the city and into the countryside. The scenery looks beautiful at times but also has an eerie feel about it, particularly during the foggy night scenes. It all lends itself exceptionally well to the horror atmosphere. Just when you think Director Paul McGuigan has shown you all his visual tricks though, he surprises you again. Later on, there’s a trip into Sherlock’s “mind palace” which is particularly great.

The hound, then. We couldn’t possibly go into details, but it’s wisely kept off the screen for the most part. Early on you get a few fleeting glimpses accompanied by some scary snarls, but like the characters who witness it, you are never quite sure what you are seeing. The creepier moments of the episode play with this brilliantly, teasing the audience and slowly building up the tension.

Guest star Russell Tovey plays his part well enough as the psychologically damaged Henry. Although for fans of Being Human, the similarities in Tovey’s performance to his character George will be a little distracting at times, particularly with the yelping.

If A Scandal in Belgravia was about Sherlock and love, then this episode is about Sherlock and fear. Benedict Cumberbatch gets the chance to show us another side to the master sleuth here as he wrestles with being genuinely scared. It’s fascinating to watch our hero crack around the edges like this. But John too, shows his own vulnerabilities later on. However, despite all this there’s still plenty of humour in the episode.

Even though this particular Holmes story has been adapted many times, this latest interpretation manages to keep it fresh and exciting and will leave you guessing right through until the end. Another superb episode of Sherlock.

The Hounds Of Baskerville airs Sunday 8 January at 8:30pm BBC1.