The Weekend's TV: They've almost cracked the Morse code

"Suddenly, there's far too many bloody dots," complained Lewis in Lewis, overwhelmed by a surfeit of clues and a shortage of connecting lines. You really would think he'd have got used to it by now, after years and years of literary detective work. He should know that whatever complications arise are only a prelude to a last-minute flurry of dot-joining, which will finally connect the mathematics don to the violent scaffolder to the autistic art student to the fetching young woman who runs hoax tours and ends up on the river bank with a shattered skull. There. Can you see what it is now? That's right: a shaggy dog, which romps around various Oxford settings before coming obediently to heel with a solution clutched in its mouth.

It gets a lot of exercise, this dog. Governments have risen and fallen in the time it takes to run through a full episode of Lewis, and yet, paradoxically, the two-hour transmission time doesn't always leave a lot of elbow room for a writer who wants to liven up the texture a bit. This episode was written by Alan Plater, always an encouraging name to see on the credits, but he had so much to do in the way of general housekeeping – dangling red herrings, revealing corpses, moving the furniture about – that you were left feeling you'd had a bit too much Lewis and not nearly enough Plater.

Still, he had fun with the young student whose conceptual artwork consisted of telling tourists whopping lies about Oxford's history, sharing with them Professor Tolkein's little-known passion for the banjo: "There are still people alive," she reassured her doubtful-looking audience, "who can remember him playing 'I Wish I Could Shimmy Like My Sister Kate'." And I doubt anyone else would have written the line in which a potential suspect offered his passion for Duke Ellington as a cast-iron alibi: "Nobody can love that music and be a party to the taking of human life." Or carved out time for a reading of the Bodleian Oath, the declaration that has to be made by anyone who wants a reader's ticket, and that includes the solemn promise "not to bring into the library, or kindle therein, any fire or flame".

They're very blasé about murder in Lewis. The chief librarian who showed Lewis through to the storeroom where an employee had just been found shot dead did so with not much more than mild exasperation, as if they were having problems with mice. In real life, the deed tends to have a much greater impact, as was clear in Storyville's film Dance with a Serial Killer. Curiously, this began with a murder that was straight out of a television thriller: a woman stabbed to death on a beach full of people, in broad daylight. Unlike in a television thriller, the police had their man pretty quickly, a drifter who'd been staying at a nearby hostel and who obligingly shared his fantasies about violent murder with the policemen who eventually tracked him down. On television, the fact that everything about this man pointed to his guilt, including his serial-killer stare and his sociopath's jumper, would have been a sure sign that he was just there to distract us from the elderly choirmistress who would eventually turn out to be the murderer. In real life, he did it, and at least 11 other murders, a fact established after dogged police work by the detective at the centre of Nigel Williams's film. Quite why Williams had made a film about a French serial killer, I'm not quite sure (perhaps he has a holiday home near the site of one of the murders), but Dance with a Serial Killer was compelling anyway, a real dot-to-dot that eventually revealed a monster. The truly scary thing about it, though, was that more than once the killer had been able to find an accomplice to his crime without even really looking hard. Without him, there would have been no murders, but there seemed to be plenty of people around who had no great interest in stopping him.

I heard someone on the radio saying that Freezing got funny after the irritating opening episode. So I checked and she was right. In fact, in parts it got laugh-out-loud funny. It was no less metropolitan in tone and no less incestuous in style but James Wood's script allows good actors to have a lot of fun, and, by extension, us too. What matters is that its spleen is in the right place, goaded by the marketable rudeness of television historians, celebrity culture and bandwagon publishing (here guyed by a miserabilist bestseller entitled Oh, Daddy, Please, No, Don't). It also has Tom Hollander as the agent, a brilliant turn, at one moment committing social atrocities and at the next dwindling into an anxious little boy. I will now write out 500 times "I must not review comedies on the basis of the first episode alone".