Gotham City has its own protector, a dark knight who lurks in the shadows and whose identity remains a secret. As district attorney Harvey Dent and the head of the organised crime unit, James Gordon, battle against the mob through legal channels, the vigilante hero known as Batman helps them in the struggle to rid the streets of scum.

An Asian crime boss named Lau is trying to work his way into the Gotham crime scene. Attempting to secure a deal with both Wayne Enterprises and the city's mobsters, he quickly attracts the attention of both the authorities and Batman. But Lau isn't the only new guy in town. A crazed, deformed character known only as The Joker interjects in Lau's offer with the mob, and quickly proves his ruthless determination. As events unfold, Gotham begins to fall victim to the Joker's insanity - with Batman and those closest to him caught right in the middle.

British director Christopher Nolan is one of those rare directors whose output is largely without exception worth waiting for. A Nolan film is to be anticipated and by the time The Dark Knight was released in cinemas in summer 2008, the anticipation was almost at breaking point. After the untimely death of Heath Ledger, the film took on a new, almost grim presence and was greeted with feverish rapture. For many weeks, the film was voted as the best film of all time on nerd site www.imdb.co.uk and at the time of writing remains in the top 5, with votes from over 300,000 people. It can be difficult to objectively review a film like this. There is a temptation to be different from everyone else, criticising whatever you can purely for the sake of doing so. It would be puerile and foolish approach. The Dark Knight is a fine film, indeed, but a masterpiece? I'm not so sure.

Appropriately, The Dark Knight feels like a "proper" sequel. The tone and pace remains in line with Batman Returns. With the caped crusader's origins and supporting characters firmly established, The Dark Knight can now settle into what Batman does best and Nolan clearly adores the subject matter. Nearly every scene is homage to the man in black, his every move beautifully shot against the landscape of a city at risk of falling into Hades. Whether gliding silently tens of stories down a skyscraper or acrobatically taking out a group of thugs, Batman has never looked so damn cool. His gadgets and weaponry are more sophisticated than ever. His tactics are fiendish in the extreme, his cunning and guile almost always out-smarting every opponent without resorting to the ridiculous antics often seen by other comic-book heroes. Crucially, Gotham feels more "real" than ever. This could be any one of the major US cities, with all fantasy elements almost entirely stripped from the setting. The result is the most stripped down, raw and realistic Batman that we've ever seen.

The Dark Knight is visually stunning. The action scenes are terrific. All are appropriately paced and technically excellent with that rare capability to make the audience's eyes widen without pumping music and endless explosions. Indeed, the film makes subtle use of music throughout the soundtrack, a sinister, repetitive piece sometimes accompanying the drama, but more often than not, simply playing out to the sounds of guns firing and people dying. Nolan always seems to know how best to use the camera. When an aerial shot is the best approach, he always selects it. When action requires perspective, he provides just the right one and yet, where detail and subtlety are in order, he knows when to use those too. The Dark Knight cements Nolan's position as one of the best directors in the business. He intuitively knows how to make something look "good" and "right" at the same time and, crucially, he only selects a project that he loves - and it always shows. The tone of the film sits well too. It's dark, serious and grisly enough to merit the 12 certificate but steps away from the real gore/violence to ensure that young teenagers will still enjoy the finished product.

Christian Bale seems even more comfortable in and out of the bat-suit than ever before. Batman is now "his" property, with memories of Val Kilmer, George Clooney and Michael Keaton now almost a distant memory. Bruce Wayne is a bit slimier this time round, publicly at least, but we remain assured of his good intentions, as much as we remain confident that he will never find true peace or love. Michael Caine's Alfred remains one of his strongest characters for years, if not forever, with the wise butler capably supporting his billionaire boss in ways that a sidekick would never normally be able to achieve. Caine's silently perpetual confidence in his employer gives the audience hope when little else does and, like Bale, the role will now always belong to Caine. Maggie Gyllenhaal is a welcome replacement for Katie Holmes as lawyer and love interest Rachel Dawes. Dawes is now hooked up with district attorney Harvey Dent, but plays an equally significant part in Bruce Wayne's life. Gyllenhaal is notably better in the role than her predecessor, providing a much stronger, more rounded performance and, as a result, a much more likeable character all round. Aaron Eckhart is surprisingly good as Harvey Dent whose character develops dramatically as the film progresses. Eckhart works well as both Dent and his disturbed alter ego Two-Face, the latter comprising a much more accomplished, much more frightening bad guy than Tommy Lee Jones' OTT turn in Batman Forever.

Needless to say, attention must turn to the late Heath Ledger's Joker, who, fittingly, becomes the young actor's most memorable role for all the right reasons. Ledger (who had already demonstrated his strong character acting capabilities) simply becomes the deformed maniac and commands attention whenever he's on screen. There are some similarities with Jack Nicholson's earlier (and also very effective) performance but Ledger takes it to a new level. From the film's early bank job scenes, it's clear that his fiendish intellect is to be ruthlessly employed throughout the narrative and the film's entire running time is largely a continual escalation of what he is prepared to do. Ledger's finest moment comes when the Joker, casually disguised in a white nurse's uniform, literally skitters and dances his way out of a hospital that is effectively detonating around him, as though he hasn't a care in the world. You really will believe that this man is completely insane.

It seems disrespectful to say it, however, but you can't help feeling that The Dark Knight has benefited from the death of one of its leading stars prior to the release. The film is, without a doubt, excellent but is not the masterpiece the world would have you believe. Never one of my favourite characters in the franchise, The Joker actually becomes quite irritating. Physically no match for Batman, the screenplay must instead resort to giving the character a cunning and ruthless intellect but the plausibility stretch is a bridge too far - could one, lunatic man, really arrange some of the traps seen here, even with hired help? Wayne now seems to be able to develop anything and everything under the sun single-handedly and a late technical plot development is just a bit too clever to fit in with the film's otherwise strong feeling of plausibility. And did Batman talk like that in Batman Begins? Who would trust a man who sounds as though he's trying to impersonate that guy who voices the trailers?? It's probably also a bit too long. At about two and a quarter hours, there was almost certainly room for some reduction here, even if, curiously, some of the action seems a little rashly edited.

The film's central themes also become tiresome. As Nolan explores the notions of heroism, good and evil it starts to feel a little jaded. As intrinsic as it is to the comic-book series, must every Batman film look so intensely at the relationship shared between the inhabitants of Gotham City and the masked vigilante? At times, I found myself longing for something a little more superficial, something a little more akin to the "KERPOW!" of the 1960s television series. Ironically, when The Joker asks "why so serious?" it's a question that many members of the audience will want to ask too.

So The Dark Knight is a good film, possibly a great film, definitely the best Batman film we've had and probably the best superhero film adaptation we've had to date. But it's not the best film of all time and it's not a masterpiece, so there.