[WARNING: Contains SPOILERS for Sherlock: The Six Thatchers.]

Culverton Smith. Millionaire. Spokesman. Philanthropist. Humanitarian. Personal friend of The Queen. Man of the People. And, according to Sherlock Holmes, the most evil man in England and the most prolific serial killer in modern history.

Normally Sherlock Holmes’ word might carry some weight. Circumstances are not normal, however, even by the rather loose definition employed when discussing the common state of affairs regarding the world’s greatest consulting detective.

Holmes has been a shadow of his former self ever since cutting ties with his associate, Dr. John Watson. His kitchen has been turned into a meth lab and he’s back on the smack… at the very least!

Perhaps most worryingly, Sherlock claims to have been talking to a young lady – Culverton Smith’s estranged daughter – who nobody else has seen! Of course, it’s not like Dr. John Watson can throw stones. He’s been seeing a woman who isn’t there himself – his recently deceased wife, Mary!

The Lying Detective is a typically twisted Steven Moffat story, where confusion reigns supreme until the final fifteen minutes, with a goodly amount of witty dialogue and thoughtful monologues along the way. Of particular note is the unreliable narrator device, which is exploited to such a degree that the viewer is forced to continue watching just so they’ll have some clue as to what they’ve been watching.

It spoils little to say that Sherlock’s suspicions prove accurate in the end – what would be the point of the story if he were wrong? As with most Sherlock episodes, however, the journey is what is important rather than the resolution. In this respect The Lying Detective succeeds.

Toby Jones proves an effectively disturbing villain, being equally capable of playing the charmer and the creeper as needed. The performance is reminiscent of his work as The Dream Lord on another Steven Moffat script – the Amy’s Choice episode of Doctor Who. Benedict Cumberbatch gets to ham it up a bit playing “stoned Holmes”, in several sequences that are directed by Nick Hurran in a way that suggests he was trying to emulate David Lynch but wound up impersonating Baz Luhrmann.

Martin Freeman gets more to do this time as Doctor Watson – not only playing the man of action but getting to interact with the rest of the ensemble more than he did in The Six Thatchers. Speaking of which, the supporting cast is still largely left on the sideline with the exception of Una Stubbs, who steals the show as Mrs. Hudson.

Overall, The Lying Detective proves to be an improvement on The Six Thatchers. Indeed, its ties to that preceding episode help to rectify some of that episode’s short-comings by restoring Mary Watson’s agency somewhat and showing the effects of her death in a way that truly make it mean something important. It also sets up one hell of a cliff-hanger heading into the Series Four finale.