Appointment with Crime is a gritty British film noir from 1946 that offers viewers an atmospheric journey into the criminal underworld of post-war London. Directed by John Harlow and produced by Victor Hanbury, the film stars William Hartnell in an impressive leading role.

Hartnell, best known for being the first actor to portray the Doctor in BBC's Doctor Who, plays the role of Leo Martin, a petty crook who harbours a deeply-rooted desire for revenge against the gang that left him carrying the can during a high-stakes heist. The heist landed him in prison, and now that he's out, he aims to make them pay for their treachery.

Robert Beatty plays Gus Loman, a stoic detective with a keen analytical mind. He walks the thin line between law and order and the chaotic world of gangland London. Loman's character brings the perfect sense of balance to the crooked world where both corruption and integrity play significant roles.

Adding to the dynamic cast is rising actress, Joyce Howard, who portrays Carol Dane, a kind-hearted, independent, and intelligent woman who unexpectedly enters Leo's tumultuous life. She forms an essential piece of this thrilling puzzle, significantly impacting the story's course through her relationship with Leo.

Amidst the gloomy and seemingly desolate cityscape, we explore the tension-filled narrative full of justice, revenge, and the ultimate struggle for one's redemption and conscience. Appointment with Crime transcends the usual 'cops and burglars' mechanics of its contemporary counterparts. Instead, it delves deeper into the psychology of its characters while keeping the audience on tenterhooks with its cleverly woven plot.

Director John Harlow demonstrates a knack for suspense and excitement, creating an atmospheric presence that reflects off the cold marriages of foggy streets and shadowy alleys. With brilliant cinematography, the visuals serve not just as the backdrop but as another character within the story, enhancing the ambiance of the entire narrative.

The screenplay, co-written by Anatole de Grunwald and Patrick Kirwan, is deftly woven, offering the right mix of curveballs and intricate detail to keep the audience engaged throughout. There's an abundance of clever betrayals, cryptic clues, and accurately timed build-ups, all of which are executed with immense capability. The dialogue, with its crisp British eloquence, resonates with the era, exhibiting the signature style of post-war crime dramas and helps build the overall aura of the movie.

The music score by Benjamin Frankel, a renowned British composer, adds an additional layer to the essence of the film. His composition successfully complements the plot's pacing and aids in amplifying the suspense, making the thriller more engaging.

Hartnell's performance as Leo shows his range as an actor, molding his character from an opportunist minion into a vengeful force to be reckoned with. His performance excellently captures Leo's emotional struggle with his past and commitment to make the wrongs right. Joyce Howard's portrayal of Carol is both compelling and empathetic. Her character serves as a beacon of hope amidst a world that is seemingly lost within its own shadows. Robert Beatty’s Gus perfectly encapsulates a man bound by duty who is ready to unfold the truth at any cost.

While the movie remains rife with tension and suspense, it also incorporates elements of romance, morality, and a strong narrative focus on human redemption. In this way, Appointment with Crime cleverly dodges and integrates various traditional noir tropes, essentially creating a cinematic experience that departs from standard crime thrillers.

Ultimately, Appointment with Crime is a riveting crime drama that takes you through post-war London's raw and ruthless underbelly. Its sharp narrative, excellent characterization, and notable performances from the cast make it a stand-out film in the noir genre. Whether you're a film noir lover, a fan of crime drama, or an enthusiast of period films, this cinema gem from the late 40s is definitely one to watch.