Bruce Willis, Justin Long, Timothy Olyphant, Cliff Curtis, Maggie Q.

Running time: 130 minutes.

***

IT'S a tough life being New York detective John McClane.

You try to do your job and catch the bad guys. But they won't cooperate: jumbo jets get fireballed, skyscrapers gutted and New York ends up looking like it's been toasted with a giant flamethrower. What's a little collateral damage, right? But then 9/11 happens and people get sore at the thought of you blowing things up, especially in New York. These past 11 years, your services are no longer required. Top that with your wife divorcing you and now your daughter won't even use your surname, let alone talk to you: who would want to be a hero?

But therein lies the very qualities of the all-American good guy: even at your lowest ebb, when your hair has fallen out and your waistline expanded with middleage, you are still ready to do your duty and defend the homeland.

And boy is Bruce Willis's John McClane chuffed to be back. He biffs, boffs and bounces his way through Die Hard 4.0, lobbing wisecracks like hand grenades:

"You just killed a helicopter with a car, " his sidekick Matt Farrell (Justin Long) says after he, well, kills a helicopter with a car. "I was out of bullets, " he retorts.

Number four is a whiteflash of action, explosions, good humour and cartoon silliness . . . the most enjoyable and least pretentious popcorn film this summer. The best moment sees McClane drive an SUV full-whack into a lift shaft in an attempt to kill bad girl Maggie Q . . . the neatest solution to the SUV problem I've met yet.

It all starts out as another ordinary night for senior detective McClane. He argues with his daughter Lucy (Mary Elizabeth Winstead) and is then sent by dispatch to collect internet hacker Matt Farrell from his house. But Farrell is an unknowing cog in an impending attack on America and his flat is the target of stealthy gunmen who want the young man dead. McClane gets him out; then chaos hits New York.

Soon, FBI man Bowman (Cliff Curtis) pronounces the immortal words that send a surge of fear and pride into the hearts of all Americans: "We're under attack."

It would be too close to the bone for foreigners to be behind the terrorism. So it comes from within . . . a disgruntled homeland security expert turned cyber terrorist called Thomas Gabriel.

(He is played by Timothy Olyphant and you would swear he is the younger, better-looking brother of Billy Bob Thornton. ) Gabriel's cunning plan is to kill Farrell then launch a 'fire sale' on America and extract a lot of cash.

For a while I thought this meant he planned to make some money from the cheap sale of smoke-damaged goods after another McClane demolition job.

But no. 'Fire sale' is the cyber term for an attack on a country, using the internet to shut down its infrastructure, financial markets and utilities. No wonder McClane looks bamboozled.

Farrell can type quicker than McClane can think and Die Hard 4.0, with its titular nod to internet 2.0, is very high-tech. It needs Justin Long's techie character to solve the computer problems so the camera can be free to follow lumpy luddite McClane as he resorts to old-fashioned body bashing. And then there's Olyphant's smooth terrorist who comes with total IT omniscience . . .

a skill that all baddies today must master to be credible. This guy can twig the entire New York traffic system at a pinch and then improvise the multi-lane management of a tunnel so it turns into a chaotic car trap for the hunted duo. He even knows how to improvise the diversion of natural gas through other pipes to cause an explosion. "You are a timex watch in a digital age, " Gabriel jibes McClane. And writer Mark Bomback has a lot of fun with this, slagging McClane's internet-age ignorance at every opportunity.

Die Hard 4.0 is careful not to wreak too much havoc on Gotham: there's a few limited-scale setpieces, and some car crashes, but the serious action is relocated to industrial sites in the country. It is very competently handled by director Len (Underworld) Wiseman and there are some slick setpieces filmed as if by a bystander running across the action. With so many summer films trying desperately to be something they are not, it's refreshing to see a dumb film play it unashamedly for what it is.