The strength of Lynda La Plante's original Prime Suspect, which held the nation captive for two nights last year, was that it took itself seriously as a piece of entertainment without aspiring to the condition of art. It wasn't too posh to have a plot. And sexism, its central concern, always felt like part of the journey, not excess baggage. The key pleasure lay in watching Tennison (Helen Mirren) get inside the head of the headcase and follow the crooked logic all the way to his door. The sequel, outlined by La Plante but written by Allan Cubitt, seemed doomed to disappoint. But, by the end of part one on Tuesday, the only problem it faced was being booked for leaving the audience in a state of indecent anticipation.
In the opening moments we cut between Tennison interrogating a rape suspect to a squelchy back yard where forensic wallahs are pulling up a skeleton by its rusty fingertips. The chirpy Gravediggers' Scene humour ('Looks like it's a female, Oscar, it's wearing a bra') is a blast of fresh air outside the hothouse interview room. Then, the door opens and we see that we are watching Tennison being watched: it's a training course. It gets a laugh, but it also brilliantly sets up the now-you-believe-it, now-you- don't rhythm of the investigation.
The plot, with its black and white herrings, kept you watching, but it was the psychological detail that made it matter: the artist reconstructing the victim's face from her skull who points out the muscle she would have used to kiss. When the father of a suspect is told his son has killed himself he blinks, apparently in docile acceptance, and then asks 'Is he hurt?' The nonsense that comes when things stop making sense.
The police were a treat: Craig Fairbrass as DI Burkin, all marrf and Trevor Brooking barnet who says darkie as easy as darlin'; John Benfield's Det Supt Kernan glowering respectfully at Tennison with his glum, rubber-glove face; and Colin Salmon who made Oswalde sexy and sensitive and himself a star. But it was Mirren that lifted the project from compelling to compulsory. A storm in a D-cup to the tabloids and once one of the RSC's most deliciously spoken Cleopatras, she exploits both sides for Tennison. She's not allowed to be sexy (the lapse with Oswalde costs her dearer than it would any man), but the sense of reined-in sensuality is powerful; part of the willed toughness that helps her survive. And she speaks beautifully, guvving with the best of them but showing a range of tone, from the gentle teasing out of a deathbed confession to the acid jests at Kernan ('I've made my decision'; 'Well, it's a bad one'). You saw what Prime Suspect 2 would have been like without her, watching La Plante's Framed (ITV) - all sound and fury and Timothy Dalton fluttering his antelope eyelashes in a frenzy of male bonding.
Even Mirren couldn't quite save part two. It didn't help having News at Ten bong in the middle of the scene where Tennison finds the crucial clue. The racism theme started to drag its feet; the campaigning politician had all the sweet understatement of a Militant vendor. And the implausibilities started forming a pressure group - would Tennison really send Oswalde on his own to confront the killer? Wouldn't the nice Jason we saw in the hospital have given any sign he was the barking hyena of Margate? Do all the Met top brass model their hairstyles on Lionel Blair?
Not everyone will have stayed up for the grand final of Come Dancing (BBC1). Which is a pity, as the only way you could hope to re-create the experience of the Penge Latin Formation Team would be to climb into the tumble-dryer with a pound of liquorice allsorts. Regular viewers knew that in the battle of London, the south had it sewn up not only because of extra sequin power but the presence of the veteran coach, Peggy Spencer. Out on the floor Rosemarie Ford, airbrushed into a lilac sheath for the occasion, introduced the couples. At one of the fancy side-tables amid the palm fronds, Charles Nove was commentating. If you filled one of the Sinden family with helium you would get Charles with his slow leak of late-Edwardian sentiments. During the quickstep, Charles was particularly pleased to welcome a foreign pair: 'It's quite a change from the wide open spaces of Canada to the attractions of Norbury.' Yes, siree. The waltz was going swimmingly for London North until Jayne's exuberant feather trim was drawn into the static between Mark's legs. From behind it looked as though he were restraining a runaway ostrich.
In the cha-cha-cha, Vicky, 19, was in the regulation slash down to the boobs, up to the groin and hang-something-dangly-down- the-back uniform. The threat to her modesty distracted from an athletic performance, though it hardly compared with the recent exertions of a lady introduced without comment by Charles as Baedeker Toff who had presumably been around a bit. The enduring mystery of Come Dancing is not the Bournemouth timewarp it inhabits, nor the fact that scores of vacant teenagers want to look like Mitzi Gaynor circa 1941, but that 35 minutes should pass every week without passion, sensuality or grace. I heartily recommend it.
The opening titles for A Paul Morley Show (C4) were by the Me Company. This came as no surprise; the rest of it was by the Me Me Me Company. Morley is one of that new breed of critics, the post-modern onanist whose motto is 'Only Disconnect'. He was deconstructing the chat show. He talked to himself a lot wandering round a studio plastered with kitsch posters (kittens, Bruce Forsyth). 'If I had my own show what would I do? How would I entertain - by being myself - how is that possible?' A woman impersonating Carly Simon gave yes and no answers to calculatedly dumb questions ('Would you feel sorry for an animal in a trap?'). I suspect Morley thinks he's a social satirist, but if you want to bring something down it's usually best to have an alternative good in mind. After the virtuoso exit of Absolutely Fabulous (BBC2), we now had Absolutely Meaningless.
Advent Calendar is the latest series of perfect miniatures from BBC2. They cheer you up like fruit gums. Every day a window opens on a clip offering an uplifting antidote to festive humbug. There was Fanny Craddock in a chiffon, bell-sleeved number ramming sausage up a reluctant turkey. 'It's my considered opinion that Christmas is just about slave labour for women, darling,' she hissed through that famous damson moue. The whole lot will be repeated on Christmas morning. Look out for Mahalia Jackson's account of 'Silent Night', where it's impossible to tell the sweat from the tears. In window 11, Santa asks a fractious poppet if she'll be taking the controls of the train she wants for Christmas. 'I'm a girl, I don't drive trains,' she snorts. Will someone please manufacture a DCI Tennison doll?