BID THY farewells to Ivanhoe (BBC1, Saturday), which came to an end with rough-hewn Athelstane descending the winding stairs from his own lying-in-state, his winding sheet flapping round his ankles. A miracle! He was not dead after all. In fact he wasn't even very ill, and now he capers round the castle, handing out his blessings to young lovers, old earls and King Richard the Lionheart, to whom he swears fealty (providing Dick promises to rule fairly over Norman and Saxon alike). I wondered whether that Ivanhoe fan, Tony Blair, has read this passage to John Prescott.

This silly resurrection was forced by Sir Walter Scott onto the producers; left to themselves they would have let Athelstane cold on the slab. But they got their revenge later, in the sweaty sword fight between boring Ivanhoe and that exciting, naughty knight, Brian de Bois Guilbert. This contest ends with Ivanhoe bringing his sword down, wallop, on Bois Guilbert's unhelmed head.

In the old days, Guilbert would have croaked his last hoarse words, as a teeny trickle of blood emerged from the side of his mouth. But not any more. These days a consultant surgeon, an arms expert and a pathologist would all be asked by the producers what it would look like were you to be whacked very hard just over the right temple by a sharpish bit of metal, weighing a stone. Would the eye come out completely? Would one see bone? How much tissue would be visible, and would it hang by horrid, gristly threads, or just divide neatly like raw steak? Once the answers were forthcoming, the make-up department (whose greatest challenge used to be Danny La Rue) would be set to work.

So Guilbert (played by Ciaran Hinds, shortly to be seen as maimed Rochester in ITV's Jane Eyre) lies there on the grass with one eye entirely missing and a huge, bloody cleft in his face, begging (understandably enough, for he has pulled his last wench I trow) for the coup de grace.

I mention all this because such intimate attention to gory truths is also an important feature of what one might call "pathologist chic". This is the new boom genre on prime-time TV, offering a mouth-watering combination of science, nudity and crime. Brand leader at the moment is Silent Witness (BBC1, Friday), in which this week's question was: "What exactly happens when someone has a shotgun fired at one side of their heads?" The answer - as Amanda Burton, the eye-narrowing, head-cocking, sexy-voiced Ulsterwoman who plays pathologist Sam Ryan, discovered - is a gelatinous red mess, with a skull hinge at the back. "I've got a nasal temperature of 32 degrees," said Sam, somehow discerning a nose, "but we'll need to recover as much skull and brain material as we can from that wall." Yum, and there it is.

Sam has plenty of good new- drama hinterland, including a sister going batty, but the most important characters are the stiffs. Bagged up on site, and then laid out on slabs, they show their all; there seems to be no difficulty with appearing completely naked, as long as you're dead. The male boxer, whose brain Sam sloshes around like someone at a guess-the-weight-of-the-cake competition, has all his kit off, including the top of his cranium. Indeed, full frontal nudity for corpses is not occasional, it is de rigueur. For cadavers it is always artistically necessary for them to be filmed in full pubic bushiness. Genitalia that are impermissible when warm, are kosher when cool.

As in McCallum (ITV, Monday), where the hallucinating, gloomy Scottish pathologist - confronted with the re-stitched, naked corpse of some poor chap who is still cluttering up the giant filing cabinet marked "Stiffs" - asks: "Is he breathing?" "Nah," replies a colleague. "We took his lungs out, remember?" And if you're not careful, we'll show them to you. Meanwhile, watch while we do a nice long scalpel incision along the line of this naked dead guy's body-hair. Yum.

The corpse spread out on gloomy journalist John Pilger's slab was the puffy, anaemic one of the Daily Mirror. In Network First: Breaking the Mirror (ITV, Tuesday), the lugubrious antipodean - dressed all in white and wielding truth's scalpel - set out to discover how the Mirror died, and who killed it. Once it was vigorous, lusty, combative - and full of John Pilger stories. Now it is just smut, scandal and gossip. Why? It was down to the four "M"s: Maggie, Murdoch, Maxwell and Montgomery. Out of greed, megalomania, political spite or incompetence they had brought about the dumbing-down of British popular newspapers, depriving the workers of the information necessary to rise up and overthrow their corrupt masters.

You see, concluded ol' Pilge, actually people don't want all this Sun crap. For instance, all these young folk from Pimlico School, who sat down in front of the ascetic, priestly Pilger and told him that they abhorred all the Fergie rubbish, all the celeb-screws-celeb garbage, all the salacious twaddle. What they wanted to know about, presumably, was the plight of striking dockers in Liverpool, and reforestation in Cambodia.

Did Pilger really believe them? Did he not think that they were wise enough to tell him what he wanted to hear? Did he not know that had Kelvin MacKenzie been sitting in his seat, the group might well have praised the Sun's irreverence, its lack of seriousness, its "sense of fun"?

And isn't that genuinely sad? This week we have had cause to reflect on the role played by the Mirror, and that great, priggish Trot Paul Foot, in the quashing of the sentences of those men wrongly convicted for the Carl Bridgewater murder. They would never have made it without Footie's persistence - and the old Mirror. But crusades no longer sell papers in Pimlico.

Prisons do sell TV programmes, however - as long as they're fictional. On Wednesday we had a prison that did not conform to small-screen notions of being banged away - as reproduced from Porridge to The Governor, via Prisoner: Cell Block H. Insiders (BBC1) is from the Lucy Gannon stable, and Gannon's success derives from eschewing the existing cliches of TV drama - then creating her own. No higher compliment can be paid.

So Gannon's prison is an open prison - ie prison, as run by the nursing staff of Holby High, all with lashings of empathy, difficult back- grounds and grainy hinterland. There is warder Woody - a high- testosterone version of Charlie Fairhead; attractive instructor Annie Whitby, who rehabilitates prisoners by thoughtfully parading on the beach clad in a tight tank-top and who has an imaginary boyfriend called Stephen at home in her seaside cottage; new, troubled screw Gerry; and loads of great prisoners.

In episode one we focused on the twitches, slow self-recognition and complex psychology of army officer turned fraudster, Mark Gordon, played by Bill Nighy in a performance that would have graced any classic drama. His desperate semi- suicidal frolic in the sea with Ms Whitby was all the proof one needed that Gannon has managed that alchemy of creating a closed situation, which is nonetheless replete with possibilities.

Just time to pay tribute, then, to the granddaddy of them all, the king of hinterland and the queen of gore. For last night saw the last in the current series of Casualty (BBC1). It opened with Charlie holding blood- spattered nurse Jude in his arms and bereaved ambulanceman Josh getting closer to the edge. For those who missed it, here is my 30-second audio synopsis:

"Jude!" "I don't need counselling!" "Come on, Jude." "Where the hell is that cardio-thoracic SR?" "I'm going to need a wide-bore kanga with a 50 mill syringe." "You can't keep running away for ever, Josh". "Yes! I've got a pulse! Come on Jude!" "I miss them, I miss them!" "I love you, Jude." Dadada da da da, daddada da da da. Casualty will be back in the spring, when - once again - the scar will be the star.