A quirky, modern hard-boiled detective story with a very smart script and a solid cast, The Big Bang has a lot going for it, but doesn't quite live up to its title. The movie is great when it hits its stride, full of clever, noir-style dialogue and creative turns. For all the pulpy, near-hallucinogenic material handed to him on paper, though, director Tony Krantz embraces a surprisingly modest tone, undercutting a lot of the film's own energy -- which is somewhat ironic for a movie with an ongoing theme about quantum physics. We open on private detective Ned Cruz (Antonio Banderas) being interrogated by three strong-arm cops (Thomas Kretschmann, William Fichtner, and Delroy Lindo). They want to know what kind of role Ned had in the series of murders they're investigating, but for that, the private eye has to tell us the whole story, from the beginning. The tale starts with a recently paroled gigantic Russian boxer named Anton Protopov (Robert Maillet), who hires Ned to track down his stripper girlfriend, Lexie Persimmon (Sienna Guillory), and the 30 million dollars' worth of diamonds she hid for Anton while he was in the clink. Soon, Ned finds himself embroiled in a plot involving the Russian mob, dirty cops, and a quantum-mechanics-obsessed billionaire (Sam Elliott) who's funding a potentially unstable re-creation of the Big Bang at a particle collider below the Nevada desert. Meanwhile, Ned is growing steadily more obsessed with the elusive Lexie, dropping by the set of a seedy porn director (played in a fun cameo by Snoop Dogg), and having a truly kick-ass, hot and sexy old-school love scene with a bewitching waitress/tattoo girl/particle physics enthusiast named Fay (Autumn Reeser). You can't help having a great time watching The Big Bang when a scene leaves things mostly to the actors. Elliott's role as the Ted Turner-eque cowboy-turned-mogul-turned-philosopher is perfect for him, and Banderas' decidedly El Mariachi-style burned-out hero reminds you why you fell in love with him as an actor back in the early '90s -- especially when he starts reluctantly waxing poetic about the parallels between a physicists' search for the particle behind the creation of all matter and the everyman's search for true love. The trouble is just that when it comes time for the director to shine -- with editing, pacing, or other smart cinematic choices -- Krantz plays it way too mellow. This is an outrageous script, and while we can all appreciate a little discreetness behind the camera, Krantz keeps things stoic at the sacrifice of what would otherwise be exciting or at least memorable content. If the film had been helmed by the Coen Brothers, or Banderas' old partner in crime Robert Rodriguez, The Big Bang could no doubt have been the fun and crazy sleeper of the summer. But as it is, it's still a little bang -- if not a big one.