The scene opens on a clock whose hands are at five to twelve. Hayley Westernra's vocals and a string quartet provide the soundtrack to the opening scene of a woman examining a throne-like chair that's so festooned with shackles that it looks like it's been borrowed from the set of a high-tech bondage film.

"You don't get extra strength," the woman says, "in cases like these."

"There are no cases like this," says Doctor Tom Jackman.

He speaks into a Dictaphone. He answers the woman's raised eyebrow with, "It's how we communicate."

The clock's hands reach twelve, and Jackman's eyes around the iris fill with blood. He straightens and seems to physically alter, his hairline changing, even—subtly—the shape of his face sharpening.

Cue credits, one after another, the screen reads;

James Nesbitt

in

Jekyll

Written by Stephen Moffat

The text intermittently cuts out, as if a distant electrical storm is interfering with the power supply. Along with the music and the oblique dialogue, it tells us that this is a Jekyll for the twenty-first century. It is also very much Moffat's story—no mere faithful re-treading of Stevenson's classic as earlier versions, such as the 1981 story featuring David Hemmings and Ian Bannen, nor a cousin to the more or less bowdlerized Hollywood versions, staring Frederic March or Spencfer Tracy.

The woman is Katharine Reimer, a psychiatric nurse with expertise, as Jackman puts it "in related areas."

Jackman has been disappearing for long periods of time, and unsurprisingly his marriage is under strain. His somewhat self-involved wife greets him with, "You might have at least the decency to be having an affair," as she hands him a set of photographs showing him getting in and out of a car. "It's one thing to come second best to another woman—but to come second best to no woman at all ..."

Claire Jackman (Gina Bellman) still clearly loves her husband, but even as they appear to be reconciling their differences, the music builds, signalling an impending—unexpected—change and Tom flees. He strips his wedding ring off and shoves it into his car's glove-box. When Jackman comes to, a semi-naked woman sits smoking a cigarette and watching him, her expression anxious. "How much do I owe you?" he says.

Afterwards, having sneaked a look at the name of the agency on his wife's photographs when she showed them to him, Jackman visits the Callendar Detective Agency. He's as concerned with the photos that his wife hasn't seen, the ones of his alter ego, and asks why Callender (Meera Syal) hasn't shown them to the woman who is nominally her client.

Using a ruse, Callender sneaks out without answering, but even as the next change looms, Jackman rushes after her. Callender confesses before driving off at high speed that she has been paid off, and that the black van that's been following Jackman, which he thinks is hers, is nothing to do with her.

Jackman is obviously rich, although precisely where his money comes from is unclear. He drives a top of the range Audi, his family lives in a large detached house with acres of gardens, and he can also maintain a London flat and pay for the assistance of Nurse Reimer. He stops by at a large, glass-fronted building where he's clearly known—the receptionist asks him if he'd like his "usual privileges." A well-dressed man stops by and asks Jackman if he wouldn't rather be doing what he does than writing about it. It becomes clear from this conversation and Katherine Reimer's later accusation, that Jackman is a scientist still using the facilities where he worked before for research—something that Hyde has forbidden on pain of "putting a bullet in his head."

Most of this first episode is all about setting the scene, establishing Jackman's dark side, and introducing all but two of the major players, such as Peter Syme, perhaps the Jackmans' best and oldest friend, and Benjamin Lennox, who tells Hyde, "In a corporate rather than personal sense ... I'm your owner." This references the earlier versions of the story, while making it clear that this is an extension of Stevenson's novella, not a re-make, by taking it into the realms of corporate badness. The only two major characters not introduced in the first episode are the mysterious old woman Sophia, who appears in episode two, and Utterson, the female head of the (frankly risible) evil corporation bank-rolling both Jackman and the whole Hyde project.

Jackman tracks down the now-retired Callender detectives and gains his back-story for the viewer's benefit, but in the process they reveal the location of the Jackman family to Hyde; until now Tom Jackman has kept them a secret from his alter-ego, fearful of the consequences to them—his stripping off of his wedding ring is so that Hyde doesn't suspect their existence. But when Claire says, "I didn't realize you had a cousin," Jackman knows that his worst fears have materialized. Panic-stricken, he leaves "Uncle Billy" a message on the Dictaphone—"stay away from my family, or else all deals are off."

The second episode opens with a flashback to Hyde and Nurse Reimer's first meeting, which allows an extended comparison both with standard split personality and with the original Jekyll and Hyde story, and sets a pattern that recurs throughout the series. Each episode either opens with or cuts to a flashback within the opening few minutes. The second episode also shows us Nurse Reimer's hidden agenda and introduces us to her other employer, the mysterious Sophia.

This juxtaposition of sequences to create mystery by withholding crucial information is an approach that Moffat has used in both Coupling and Doctor Who, but those are established series, where the viewer is likely to be more forgiving of writerly tics. In Jekyll, by jumbling the sequences Moffat creates mystery but also alienates casual viewers.

In each successive episode, the flashback covers a greater period of time, like a hypnotist's watch swinging across an ever-greater arc. So the third episode opens with a blood-soaked Jackman falling out of a tree, and jump-cutting through the scenes that led to him being there, which also provides many opportunities to play with the viewer's expectations.

It's also the episode in which Claire learns the truth about her husband, and after some inevitable but frustrating denial—particularly given the inconsistency with which Claire seems to accept, then deny the evidence of her own eyes and ears as Jackman physically alters his appearance—accepts the truth. She is as irritatingly self-absorbed as ever, and it's typical of her that when she learns the truth her reaction is not to sympathize with her husband, nor to worry about the effect of this on their sons, but instead to think solely of herself and to ask, "How many have you had? How many? How many girls, women, little boys. How many?" It's self, self, always self with Claire Jackman.

But she finally stops whining and starts fighting, showing us a previously unsuspected, appealing side that must be what attracted Jackman to her in the first place.

The attraction is brought centre stage with the fourth episode, which flashes back to seven years earlier. Claire has been set up by a friend on a splendidly awkward blind date with Tom, and the viewer finally gets to see what the initial attraction was. He's a monosyllabic but high-earning researcher, while she answers his opening gambit of "What do you do?" by firing off, "Rich men." She hides his shoes so that he can't flee the party until she's ready to leave with him. But this is no mere mercenary pick-up; less than a year later she gives birth to a son—or rather, sons, for despite only one heartbeat registering on the scans, she bears twins. Later on, when the Jackmans run into trouble on a seaside holiday with a gang of thugs bent on humiliating Tom through her, it is she who consoles him afterwards, telling him that she was proud of the way he didn't respond and escalate the trouble. The episode ends with Claire throwing scalding coffee in the face of the Corporation's head villain, and the transformation from Narcissus to lioness protecting her pride is complete.

Episode five swings right back to 1886, opening with Doctor Jekyll meeting with Robert Louis Stevenson. As with many other writers, Moffat's mastery of current dialogue betrays him when asked to write Victoriana (the use of "contact" as a verb is a twentieth-century one, as is "connected" to mean "acquainted with"). The meeting is for Stevenson to hand over a draft manuscript of the famous story. Jekyll has had Stevenson write a fictionalized account of his life. He tells the writer, "It is no tale, it is a trap."

Hyde's superhuman powers increase. He starts to physically flashback, first to witness his marriage from an external point of view, then back to 1886, swinging backwards and forwards in time. He listens to Stevenson talking to his great-great-grandfather, and writing him a note. He reads the note: "There is no potion. It was the girl."

The girl is the maid, Claire's doppelganger. When Jekyll changes into 1886 Hyde, he becomes aware of 2007 Hyde, and turns to stare at him. "She keeps you weak," he tells his future self. "As long as she is in the world, you are weak." He takes the pillow and covers the girl's face with it.

Back in the present, Sophia asks Claire, "When was the first moment you knew that you could kill?"

"When I held my children," Claire says.

Hyde's mother nods. "We call it love," she says.

It is the love story between Claire and Jackman / Hyde that is the key to the whole story, and had it been put centre stage, it would have made Jekyll into a fundamentally different programme. But instead, the producers have used Moffat—perhaps the hottest property on British TV—and Nesbitt's names, to green-light an almost comic-book ratings-chaser that's indistinguishable from any programme made by Britain's independent television channels. Which is odd given the BBC's mission is to make programmes that "inform, educate and entertain," still built into even the latest Royal Charter of 2007.

By way of explanation for American readers: the BBC is funded by a licence fee levied on all television owners, and in return shows no commercials, apart from endless plugs of their own output. This gives them the artistic licence to pursue worthy but obscure programmes such as BBC4's wonderful strand on British SF at the end of 2006, which no commercial station would have touched with a bargepole. Their defence against losing this fee is the Royal Charter, renewed this year.

All too often the current response to the Reithian mandate has been to concentrate on the entertainment, and to make programmes like Life on Mars—innovative enough for mainstream television that it assuages their critics. The Charter therefore doesn't completely preclude populist shows, as the renaissance of Doctor Who proves, but Who was in itself a project that no independent station would have taken on—it's only now, after the BBC has blazed the way and SF is manifestly fashionable, that series such as ITV's Primeval are being commissioned. Even Torchwood, no matter how lamentably executed, at least tried to do something different. Jekyll has no such ambitions. And that's the most disappointing thing about it.

While it ticks the Reithian box to entertain in spades, there's nothing at all innovative about it, let alone informing or educating. That's true of much other television drama of course, but with "The Empty Child," "The Girl In the Fireplace," and latterly "Blink," Moffat has shown what he can do, and if his name is going to be used to green-light dramas, then he needs to watch out that he doesn't devalue it.

Instead the viewer gets flashbacks and interminable flashes of Hyde baring his teeth (to signify that he's a wild animal), plus all the other tricks that mediocre directors who confuse style with substance use to pad scripts out to the requisite length. Ultimately this, the switch-back plotting, and the preposterousness of the SMERSH-style Klein & Utterson Corporation undermine credibility almost fatally.

As I watched bullet after bullet being pumped into Hyde's body with no apparent immediate effect, my immediate thought was, if he does die, what's to stop him coming back? As with bad fantasy, there seemed to be no rule that Moffat couldn't suspend at will, and without prior warning.

Moffat's strength is his set-pieces, and the brilliant alternation between humour and chills. But he struggles to paper over the cracks in the story. Part of the problem may be that there is no Russell T. Davies to provide sense checks on the writer's at times wilder flights of fancy—or it may be that producers MacKinnon, Cameron, and Taylor are actually the problem.

Those edgy credits also tell the viewer that this is a name-driven production, with both actor and writer getting star billing. But although Nesbitt may be easier to sell overseas than a better but lesser-known actor, he doesn't have the range to play two characters without lurching into Jim Carrey-esque over-acting. He's pleasant enough as Jackman, though, and to be fair Gina Bellman and Dennis Lawson are good enough to almost redeem Jekyll.

Jekyll has caused genuine consternation among viewers; one said to me, "I don't know whether to dismiss it as utter crap or to call it a masterpiece. Which is it?"

The answer is that it's a little of both. At times it's utter bilge, and at other times it veers into nothing less than brilliance, and its those flashes of what-could-have-been that are so frustrating. One thing it isn't is boring—in fact it's hugely entertaining. But prepare to suspend your sense of disbelief. Better still, club it unconscious.

Colin Harvey is the author of the novels Vengeance, Lightning Days, and The Silk Palace (due out in September). He is currently working on Blind Faith, a thriller with the slightest speculative twist, set in Brighton in July 2005. He also has a day job, but it’s not very interesting.