Mike Myers, Eddie Murphy, Cameron Diaz, Antonio Banderas, Julie Andrews.

Running time: 92 minutes.

**

THE fish are jumping. The cotton is high. Your daddy is SSIA-rich and your mother goodlooking. Yes, it's summertime . . . but if you are a cinemagoer, the living is queasy. 2007 will be remembered as the summer of threequels . . . a phenomenon that has choked the air supply. Till now, I've tried to avoid whining, but after so many insipid, flat and overblown films . . . enough to make you want to Polyfiller your eye sockets . . . I feel the need to point out some home truths: threequels are not just suffocating us in our seats, they are strangling cinema too.

How can this be, you might ask?

Pay attention and you start to notice a disturbing trend that points in one direction: sequential blockbusters are the new television. (And none more so than Shrek the Third). Look at the way they recur with episodic familiarity, with the same characters and always that fawning need to please, which ensures that everyone should go and nobody be offended.

A film no longer has a beginning and an end: like television, it's a series of artificial highs and lows that paw at our leg for attention and keep the sagging viewer awake. It's careful, too, to leave things open so the next instalment can roll on.

And, like television, we go back to see these sequels because we know and care for the characters.

But this dampens our expectations . . . the mystery has evaporated.

There's no getting to know for the first time, over 90 minutes or so, the differing shades of character.

And deep down we are comforted by the knowledge that our heroes will be OK because they got through the first two films. (And there's always a fourth instalment to come. ) But the best cinema is not comforting. The best contains that element of surprise . . . the knot in your stomach that keeps you on the edge of your seat in the dark because you care so deeply about the characters you are seeing, you worry if they live or die. That feeling is largely gone from threequels and so they take on the easygoing familiarity of television. And if there's no novelty any more, no genuine surprises, then the films stop speaking to our imagination.

And that is a very bad thing.

Still, people defend this. Fondness for the first film usually carries sympathy through to the third . . . a sentimentality that says: these films are FUN, what's wrong with you? But fun is always about not knowing what happens next. And if this is all people expect from their cinema, you can expect it only to get worse.

Sequential blockbusters are now clogging up the screens in a way that was unthinkable even 10 years ago. It's not so much like sewage polluting the water supply as sewage becoming the water supply.

And so to Shrek the Third, the latest of these cynical, money-gobbling threequels. The green ogre (voiced by Mike Myers) has got a lot on his knobbly hands: he's now married to Princess Fiona (Cameron Diaz) and this has made him content. But King Jarold (John Cleese) is dying and Shrek has to caretake the kingdom of Far Far and Away and is making a hames of it; his wife is pregnant and this sends him into tizzy of pre-parental anxiety; the talking Donkey (Eddie Murphy) and the sabre-rattling cat, Puss 'n' Boots (Antonio Banderas) trail after him making life a misery. And then he has to shoulder all that expectation for this third film. No wonder Shrek wants to go back to the peace and quiet of his swamp.

Then King Jarold dies and he names Shrek as the successor to the throne. Terrified, he ships out to find Fiona's cousin Artie (Justin Timberlake), a slacker who is the only true heir. While he's gone, nasty Prince Charming (Rupert Everett) stages a coup with a cast of fairytale baddies he rounds up at the unhappy hour in the pub.

Another problem Shrek will have to sort out too.

So Shrek the Third is a parable about growing up and taking responsibility . . . a theme aimed squarely at the 20-30 age group who will identify with most of his problems. But strenuous efforts were made to keep all ages entertained: golden oldies get a tailored soundtrack featuring Wings, Led Zeppelin and Harry Chapin;

teenagers get all that knowing pop-cultural skit; and there's enough slapstick to keep the kids tumbling.

The result is a lacklustre family film which appears to have been written by a focus group. The visual flair is intact, but the jokes come forced and often secondhand . . . would Mel Brooks be entitled to royalty cheques for stolen film gags? And the castle showdown has the freewheeling excitement of a cart stuck in a swamp.

That said, it is not without its moments: there is a glorious dream sequence in which Shrek imagines he can't cope with hundreds of destructive Shrek babies taking over his house; and there's a scene in which Pinocchio, trying desperately not to lie, strings together an increasingly complex set of double negatives which is bone-shakingly funny. But two great scenes don't make a family cartoon and Shrek the Third is pushing its luck.

Write it off as another victim to the inescapable law of diminishing returns.