I don't normally review individual Jeremy Brett episodes that aren't feature-length, but for this I'm making an exception. The biggest reason is that it's superb. The secondary reason is that I own other adaptations with which I can make comparisons. There's one with Peter Cushing. Terror by Night with Basil Rathbone also owes it a slight debt. I also don't have the 1923 Eille Norwood silent or the appropriate episode of the 1999 animated series Sherlock Holmes in the 22nd Century, which seems to have stuck to the canon with confusing fidelity.

Not content with being a great Sherlock Holmes adaptation, this is the best Christmas story I've ever seen. More specifically, it's a Dickens tale. I don't mean that it's a crossover, but that's the tone it's aiming for. We have lovable eccentrics and the long-suffering poor in a snowbound Victorian London tale that could make a cynic vomit. Sentimental? Yup. Heartwarming? Got it in one.

The original story is simple. Commissioner Peterson finds a blue carbuncle in a Christmas goose, whereupon Sherlock sets out to learn how it got there. That's fine as far as it goes, but this adaptation expands on that considerably. We begin with a dreamlike sequence of crimes and murders, all perpetrated for the sake of the carbuncle. It has seen blood. After that we find ourselves with a vicious old hag of a countess, staying at the Hotel Cosmopolitan and about to lose her most treasured possession. It's a smaller role than her equivalent in the 1968 version, but she's played by Rosalind Knight! I didn't recognise her without her spectacles, but I love Rosalind Knight. St Trinians, Eskimo Nell and two early Carry On films. If only she'd been less odd-looking, I'm sure she'd have been everywhere.

We soon see a good man arrested for something he didn't do. Thanks to a criminal record which he's since put behind him, he's soon looking likely to go to prison for a large number of years and lose his wife and children. He tries explaining to the idiot detective who arrested him, but only gets himself another round of questioning as to the whereabouts of the jewel. Most of the episode is charming, but what happens to this man definitely isn't. Nevertheless Holmes and Watson never meet him. They simply have their adventure as Conan Doyle described... but at the end, once they've lured the real thief to 221B Baker Street, there are a couple of moments where Holmes absolutely thunders. He's angry on behalf of a wronged man he's never met! That gave me a chill down my spine. It's one of Jeremy Brett's finest hours, which is saying a lot.

All that I love, but on top of that, the episode's hilarious. I was just about wetting myself. Fun with a goose! The commissionaire's surprise at a £1000 reward! "We must not deprive those we love. Or even those to whom we are married." Holmes's hat deductions also had me in stitches, with Jeremy Brett and David Burke playing the hell out of every line. I can't imagine a better version of that scene.

The minor characters are charming, not to mention played by strong actors. Ken Campbell plays the thief whose sister calls him "Jem". Admittedly that's straight from the original, but it struck me as an amusing name for a man who's stolen a gem. His real name's James, of course. However the most surprising touch is the casting of one Frank Middlemass. You might not have heard of him. That's understandable. He appeared once in the Cushing series and just once in this one, but both of his episodes were adaptations of The Blue Carbuncle! He loses a goose in 1984 and picks it up sixteen years earlier. How cool is that? I'd love it if someone edited together a version with both Middlemasses.

My only niggle with the acting is what the uncharitable might call mugging from Arrested Bloke's Wife, which made the final shot a bit sentimental even for me. However what the hell. I should also note that my brother didn't like the episode when I played it to the family, which suggests either that everything is subjective after all or that he's mad. (Hint: he's mad.)

This is a charming story about good people, with a wrongly accused man to stop it getting cloying. It's strongly emotional, but also full of comedy. Plus of course I have to mention the production values. Of course there's nothing wrong with watching a creaky old production on obvious BBC sets, but this is beautiful. The Victoriana, the snow... everything. Oh, and the climax mimics Paget's original illustration. I realise I shouldn't go singing this thing's praises so much or I'll just set up false expectations, but I'd say this one episode is good enough to justify buying the Granada series DVD boxed set. It's pretty much the definition of Christmas spirit, creating a fairy tale glow with its compassion and forgiveness. I have a new annual tradition.