Sherlock: The Sign of Three - BBC 1 TV review

Sherlock returned in double-quick time tonight with another nicely titled episode, The Sign of Three,which saw Watson (Martin Freeman) marry Mary Morstan (his real life partner, Amanda Abbington). Much as I've enjoyed previous episodes in the series, I think this is the one I've relished most. It was crammed with good things, and above all, it was great fun. That matters, because the central point about Conan Doyle's Sherlock Holmes stories is that they were great fun, and all the best detective fiction (whatever its other virtues may be) is highly entertaining..

I love the way the writers take aspects both of the Conan Doyle stories, and detective fiction from the Golden Age, and refresh them, cleverly and wittily. Tonight, for instance, we had a "locked room" mystery, countless neat deductions, an idea borrowed from Agatha Christie (a murder committed by way of rehearsal) and a plot line founded on Dorothy L. Sayers' theory that Watson's middle name was Hamish. Great stuff.

Mark Lawson wrote a fascinating piece in The Guardian the other day, ruminating on the festive season episodes of Doctor Who and Sherlock, from the prolific and talented Steven Moffat and Mark Gatiss, and the way that fan speculation (on blogs, for instance) seems to have influenced the writing. Like me, Lawson admires their achievements, but suggested that one risk of the writers' approach is that they cater increasingly for the more diehard series fans, rather than the typical viewer. His point is well-argued, but I think it is more persuasive in the case of Doctor Who than Sherlock. It seems to me that detective fiction tends to be more structured than sci-fi, and tends by its nature to impose rather more discipline on the writer.Much as I enjoy Doctor Who, I feel sometimes that the stories tip over into self-referential self-indulgence (and this was my feeling about the Christmas special), whereas in Sherlock, the self-indulgence which is undoubtedly present does not get in the way of the story.

Part of the cleverness of The Empty Hearse lay in the multiple solutions to the mystery of Sherlock's survival, and this device was not just a nod to fan obsessions but also, and more significantly, to the Golden Age tradition of multiple ingenious solutions to a given mystery. Anthony Berkeley was the master when it came to multiple solutions, but Agatha Christie, the excellent John Dickson Carr and others (including, in one wonderful post-modern take on the Golden Age story, "Cameron McCabe") also played games with their mysteries to great effect. Other than Jonathan Creek, I can think of no television show which has played games with the genre so often and so well as Sherlock.