The film's one unintentional irony is that we have to believe that 40-year-old Downey and 29-year-old Monaghan are contemporaries. Well, there's plenty of bang bang here - but kiss kiss? Downey is Harry Lockhart, a guy who has always carried a torch for his high-school crush, Harmony (Michelle Monaghan), who astonishes him by turning up in LA, all grown-up, trying to break into the movies (of course) but obsessed with solving the mysterious death of her sister who also moved to the big city after abuse at the hands of their father. The title is even taken from a celebrated critic: Pauline Kael, who reported seeing the phrase on an Italian film poster, and gleefully seized on it as the very essence of the movies. 'I'll be your narrator,' Downey snaps at us, like a resting actor waiting tables and distractedly getting your order wrong while waiting for a callback.

It's especially in love with the nervy and funny authorial voice assigned to the male lead, a frazzled hoodlum played by Robert Downey Jr. It's actually a very writerly film, incessantly displaying a preoccupation with its own storytelling structure and cheekily blowing the lid off other movies' tropes and wiles, like Penn and Teller exposing magic tricks. Now, under the production auspices of the crash-bang maestro Joel Silver, he has directed his first movie: a violent, neo-Chandleresque LA thriller with a convoluted plot, lashings of hellzapoppin' comedy, and a design that absorbs the pulpiness and cynicism of Quentin Tarantino, Elmore Leonard and Modesty Blaise. Along with Joe Eszterhas, he is one of the very few Hollywood wordsmiths you can imagine, as it were, lounging cheerfully in a jacuzzi frothing with greenback dollar-bills. Shane Black is the screenwriter who enjoyed stunning commercial success with the Lethal Weapon movies from the 1980s. A sses don't come much smarter than this.

Kiss kiss bang bang