Michael Mann's 1986 Manhunter (based on Thomas Harris' Red Dragon) allotted just three scenes to Brian Cox's Lecktor, subtly manipulating events from the cold white confines of his cell. The Silence Of The Lambs gave us a larger window on him, but Anthony Hopkins still has less than 25 minutes of screen time in that cunningly constructed movie, and for most of it he remains incarcerated, his style tightly cramped, his role more provocateur than agent.

Ridley Scott's Hannibal sets him loose, and though we have to wait some while to get a good look, he doesn't need to steal a film that already belongs to him in its entirety. This is in every sense a Lecter-fest, a gourmet banquet in which we're invited to gorge ourselves on Hopkins' performance. We pick over fetishised bits of Lecter, selecting and savouring the choicest morsels – his slurring relish of the name "Claariice", the way he glides through décor as if conducting an opera. It's like having an old friend for dinner.

The gastronomic pleasures of Scott's film are considerable, but it makes the same basic mistake as the novel in offering Lecter up to us on a plate. He's defanged, familiarised, paradoxically less dangerous at large than he was inside bars. He's also, despite his central role, a disappointingly passive figure, on others' agenda but not initially setting his own.

Every other character wants a piece of him as much as we do: Starling (Moore), in disgrace after a bungled drugs raid, is assigned to track him down; his only surviving victim, the horrifically mangled Mason Verger (Oldman), has been plotting a hideous revenge; and an Italian detective, Pazzi (Giannini), is on to him in Florence, intending to claim the reward from Verger. Lecter, in the middle of all this, quietly enjoys himself under the false identity of Dr. Fell, a Renaissance art scholar. He attends the opera, goes shopping for custom-made hand lotion, and sips espresso in the Florentine piazzas.

Scott and his screenwriters (David Mamet and Steven Zaillian) have wisely eliminated a lot of the epicurean cultivation that gets name-dropped in Harris' novel. They preserve, however, the impeccable taste of the doctor's criminal instincts. His victims in this outing are all killed because, as enemies, they have to be, and they're sufficiently rude, interfering or hostile to deserve what they get on some level. His discrimination is, in fact, too rational this time – another respect in which he's sanitised and made safe as a protagonist.

Lecter has always been a chillingly civilised madman, of course, but in Manhunter Will Graham still bears the scars of being attacked by him, while the guards he shreds to bits in Silence are also just doing their job. Hannibal, by contrast, takes the cordiality of his relationship with Clarice and makes it his default characteristic, except when antagonists deliberately get in his way.

The strongest part of the novel and by far the strongest of the film is the Florence section which forms the middle third. Scott and cinematographer John Mathieson fall in love with the city, bathing its streets in beautiful blue light, and an opera scene (with a specially commissioned aria by Patrick Cassidy) takes the breath away. The Venice of Don't Look Now (1973), Death In Venice (1971) and The Comfort Of Strangers (1990) is a reference point Scott has acknowledged for this visualisation, which sees a European city's seemingly ageless grandeur rotted away beneath by morbidity, obsession and death.

Giancarlo Giannini's performance is very important to this part of the film, and superb. The detective Pazzi is the most plausible and least grotesque of Lecter's enemies, fatally corruptible but three-dimensionally human, and his (literal) undoing brings with it the film's only twinge of pathos. There's a sweaty desperation to all his scenes, nervously surfing the FBI's most wanted list for information, ringing from a payphone to ascertain details of the reward, and assigning a street thug the task of securing the doctor's fingerprint.

Scott, whose failure to generate suspense is a major shortcoming elsewhere, gets it ticking brilliantly here. At this early stage, we haven't yet seen too much of Lecter – he's still inscrutable enough to keep us apprehensive, expecting the detective to be discovered and dealt with at every turn. Pazzi is terrifyingly exposed at that payphone, with his back to passers-by, and the composition of the shots keeps nudging us to look anxiously behind him. At moments like this, Lecter emanates immense danger precisely because – like TS Eliot's Macavity – he's not there. The more he appears on screen, the more it's possible to get a fix on his movements and reassure ourselves that we know what he's up to.

Our collusion with Lecter is a squeamish necessity as the movie progresses, in part because he's pitted against a nemesis as deeply unsavoury as Mason Verger. Gary Oldman, supplied with the waxily repellent face of a melted doll, is extraordinary, but the character remains a means of diverting that squeamishness onto something even worse. The doctor despatches his foes with suave calm and, despite the anatomical ingenuity of each death, a courtly lack of viciousness, even in the grisly climax derived from the book. Verger is the one preparing a carnal, vengeful feast, salivating over the prospect of his enemy's slow consumption by wild boars.

Not only is Lecter much less interesting as the central figure than he was lurking in the periphery, whispering into Starling's ear, but the reverse holds true of her. She's reached a career ceiling, her progress halted by the bungling of the raid and the spiteful opposition of Justice Department watchdog Paul Krendler (Liotta), whom she once romantically spurned. Being reassigned to Lecter is a clear step down, a disappointment mixed with secret, tingling excitement at the prospect of coming into contact again with that brilliant mind.

This would be a fascinating way to develop Starling if we were allowed to witness the hunt for Lecter through her eyes, but we're not. She retreats and is sidelined. The vulnerability which formed the keynote of Jodie Foster's performance is gone, giving way to Julianne Moore's strange, steely reserve. Moore is right for the film, but the film is wrong for Starling – it reduces her, dismantling the empathy set up so powerfully by Jonathan Demme. In his film, when Lecter got inside Starling's mind, he was inside ours; in Scott's, we're privy to their conversation, but no longer part of it.

It's a film of fittingly operatic excess. But in the end Harris and Scott have just made it too easy to enjoy Lecter's company. His flamboyance is indulged, but he becomes, like all heroes, predictable, denuded of the very unknowability which made his menace riveting in the first place.

Tim Robey