The key to enjoying the fourth installment in this testosterone-fueled franchise is accepting that it's a live-action cartoon that makes no effort to conform to the laws of gravity, plausibility or common sense — it's enough that it seems to hang together during the infrequent quiet moments when thinking is possible. Even the title — a play on New Hampshire's notoriously belligerent state motto — doesn't make a lick of sense. But it sounds cool, and that's what counts. We last saw blue-collar cop John McClane (Bruce Willis) giving a cackling German terrorist what-for in DIE HARD WITH A VENGEANCE (1995), and 12 years later he's older, crankier and a lot less gung ho about hurling himself into the fray. But somebody's gotta do what a man's gotta do, and McClane is the man. It's July 3 and the FBI needs help rounding up the usual hackers, including scruffy, authority-hating smartass Matt Farrell (Justin Long). All McClane has to do is drive Matt to D.C. and hand him off — simple stuff until the bullets and insanely athletic baddies (including French parkour-iste Cyril Raffaelli) start flying. "Is the circus in town?" McClane howls. Well, yeah, complete with incredible flying cars, heavily armed acrobats, a high-kicking kung-fu cutie, a black-clad ringmaster orchestrating Armageddon for fun and profit, and a blue-suited swarm of government clowns whose impotent efforts to contain the spreading disaster provide the film's easy laughs. By the time McClane and the geek reach Washington, chaos is unfolding: Someone is systematically disabling or shutting down air-traffic control systems, the street-light and electrical grids of major cities, and the country's telecommunications network. "It's a fire sale," whispers the awestruck Matt, a total shut-down, and he unwittingly helped it along when he wrote that mutating encryption program for an anonymous, sultry-voiced employer. With federal agencies blundering around like drunken monkeys, it falls to McClane — an analog weapon in a digital war — and his reluctant sidekick to find the man behind the pandemonium. Their quarry: former government-security expert Thomas Gabriel (Timothy Olyphant), who, in the wake of 9/11, advised his bosses that America was pathetically vulnerable to computer terrorism and was repaid with total career ruin. And we all know what happens next: McClane blows stuff up (notably the helicopter he takes out with a fire hydrant and a stolen cop-car-turned-flaming-missile), battles the kung-fu cutie (Maggie Q) in an SUV that's hanging down an elevator shaft, goes mano a mano with a fighter jet, and pursues Thomas, who's not only tried to short-circuit America into the Stone Age but also had the audacity to kidnap McClane's estranged daughter (Mary Elizabeth Winstead). Directed by propman turned filmmaker Len Wiseman (UNDERWORLD), it's brainlessly exhilarating until the fighter-jet scene, at which point the high-octane idiocy becomes too preposterous to bear... and there's still a solid half hour to go.