This weekend's episode found Sherlock in hammy need of a case and a nicotine patch, jumping around 221B and driving Watson and Mrs Hudson to distraction.
Fortunately, just when Sherlock's wriggling was starting to get just as wearing for the viewer, a client mercifully appeared to tell his tale in his own time - 'but quite quickly' as Sherlock instructed him.
This was a man who had lost his father on the wilds of Dartmoor 20 years before, to a gigantic red-eyed hound, whose footprints had now appeared again to Sherlock's terrified client.
Yes, we were into 'Hounds of Baskerville' territory, with writer Mark Gatiss's contemporary take on the literary classic. Bizarrely, it was only once Holmes was persuaded to leave his beloved London and visit the beautiful moor, that he became more like his usual charismatic self, and everything settled into more relaxing viewing.
And more bizarre, too. Holmes and Watson found themselves traipsing through misty woodland - good preparation for their upcoming big-screen Hobbit turns later in the year - and in some distinctly Dr Who-esque laboratories, home to genetic testing, and to an overlong scene where Watson ended up locking himself in a cage to escape the fabled hound.
Writers Moffat and Gatiss have revealed that they're keen to bring the best-known Holmes classics to their multitude of fans, but this episode proved that some of the Conan Doyle stories are harder to shoe-horn into modern-day telly than others.
Of interest was Holmes' flash of self-doubt when he had reason to doubt his own senses (later explained by hallucinogenic vapours - phew!). However, the fact that Baskerville felt slow at times, despite all the usual wit, word-play and narrative twists, is testament to the incredibly high expectations we've come to enjoy of this popular pair.
Sherlock's deductive powers got their usual display. "Of course I'm a show-off, that's what I do," he told Watson, before embarking on a Marcel Marceau-like rendition of Minority Report gesticulation, which we can only guess Mr Cumberbatch took some persuading to execute. But there was no let up. Despite such foliage, it amounted sometimes to joyless bullying of those intellectual inferiors around him which, after the banter and romance of last week, was a little bit disappointing.
Without the cheeky Lady of the previous episode, it was left to Watson to keep Holmes in check, even reminding him not to "come over all cool with your cheekbones and turned-up collar". Here's hoping the collar stays firmly up and they go out with a more quirky bang in next week's final send-off.