Your mission: find a plot

If it doesn't have a "wow" factor, a summer blockbuster can't hope to survive in the marketplace for long.

So at least director JJ Abrams has produced some appropriately eye-popping thrills for the third instalment of this popular franchise.

He is helped in his goal by Vic Armstrong, legendary James Bond stuntman, who helped coordinate the action.

Tom Cruise again takes the part of superagent Ethan Hunt, now retired, who is recalled to the colours to save the world.

We watch as Hunt swoops from skyscrapers like a latterday Superman, painfully fights an explosive device implanted in his head and is given 10 seconds to divulge the whereabouts of a device that is going to do something terrible to us all.

Other key scenes include one in which a drone blows up a traffic-clogged, four-mile long Chesapeake Bay Bridge, with a chopper picking off the stragglers.

Another sees a helicopter fly (with Jonathan Rhys Meyers as the intrepid pilot) through a huge wind farm chased by heat-seeking missiles. Cruise is, naturally, in the middle of it all.

It's a tough job starring in this sort of movie, particularly when you insist on doing some of your own stunts.

Of course, there are ways of accomplishing these feats of derringdo nowadays without hurting a fly, thanks to computer effects. But Cruise gets through the part with high professionalism.

And that familiar, rather glacial expression of his is sometimes used to splendid effect, as when he walks through the Vatican in a cassock, after scaling the walls of the eternal city rather too easily for any Pope's comfort.