When Bob Kane created the character of Batman in 1939, the world of superheroes would never be the same.

Kane introduced a zone of shadow into the gleaming universe of supermen, a hero, in other words, who made darkness his primary characteristic.

The pedagogical message of superheroes, as defined by Umberto Eco in Apocalittici e Integrati, began to falter with Batman.

Batman was a hero who used very unorthodox, often violent methods; he possessed no superpowers but only used strength, agility, and devices he conceived himself.

Batman, more than any other superhero, immediately fascinated the world of cinema, so much so that many filmmakers transposed his dark myth onto the big screen: Lambert Hillyer oversaw his adaptation into a film serial in 1943 together with Kane himself, then it was Spencer Gordon Bennet's turn in 1949, then Leslie H. Martinson in 1969 with the first feature film dedicated to the hero of Gotham City titled "Batman," then it was Tim Burton's turn with the two films Batman (1989) and Batman Returns (1992), then Joel Schumacher with his two works "Batman Forever" (1995) and "Batman & Robin" (1997).

Finally, Christopher Nolan arrived with his precious trilogy: Batman Begins (2005), The Dark Knight (2008), and The Dark Knight Rises (2012).

Over the years, the character's soul has transformed, essentially shifting from a pop icon to a dark antihero, with a gradual metamorphosis whose highlights were realized in Burton's and Nolan's films.

But if Tim Burton's Batman is a kind of social cornerstone for Gotham City, interested in the city's life, having friends, and with his house always frequented, Nolan's Batman is an ascetic, sociopathic, and subtly misanthropic figure; he appears in society only to validate his public image, but his ideal habitat is the night.

Nolan's accentuation of the Batman's darker tones becomes the leitmotif of his trilogy and, so to speak, the narrative fulcrum.

The film opens with a spectacular bank robbery sequence, entirely shot in high definition, carried out by a mysterious group of masked men who eliminate one another during the heist, until, at the end of the robbery, they reveal the true and only mastermind: the Joker.

Batman and Commissioner Gordon investigate the robbery, aided by the new district attorney Harvey Dent, a brilliant man of action who ventured into politics.

The robbed bank was actually a huge deposit of mafia money, and criminal organizations call a meeting to capture the mysterious Joker.

In the middle of the summit, the Joker makes his appearance before the bosses of Gotham's gangs, and strikes a pact with them to kill Batman, the one truly responsible for the decline of organized crime.

Thus begins a long tug-of-war between the two opposing factions: on one side Joker and Gotham's criminals, on the other Gordon, Batman, and Harvey Dent.

The Dark Knight is a work in which the superhero is a mere corollary to the central figure of the villain (in this case, the Joker himself) who remains firmly at the center of the scene and who, with his poisonous and distorted aura, holds the reins of the story.

Nolan's direction is sumptuous, masterful in transposing Gotham City's gothic atmospheres onto film, reverberating them onto the souls of the protagonists who undergo a kind of slow semantic poisoning.

Essentially, all the characters in this film enter a decline that degrades their personality, as if their identities were inexorably corrupted by the Evil that hovers over the metropolis.

The performance of the late Heath Ledger is memorable, rightfully entering the history of cinema.

The scene in which he stands up to Batman during the interrogation is truly thrilling, and the use of light in the sequence is marvelous: the Dark Knight materializes behind the Joker, blending with the room's shadow, strikes him violently from behind, and begins an interrogation that very soon turns into a farce.