ISN'T IT always the way? You wait an aeon for a killer vegetable film then two come along at the same time. A week after M Night Shyamalan embarrassed himself with The Happeningwe are offered another thriller in which plants turn nasty.

Adapted from a novel by Scott Smith, whose superb A Simple Planwas impressively filmed by Sam Raimi in 1998, The Ruinsconcerns a group of middle-class American youths and their unhappy interactions with an ill-tempered Central American vine.

The gang - variously snappy, silly and sarky - meet a German tourist in the opening scenes and foolishly accompany him on a journey into the jungle. Besieged by angry natives, who don't take kindly to their intrusion, our heroes take shelter atop a Mayan temple. Before too long, vines begin inching their way towards their smug, culturally imperialistic limbs.

To be fair, The Ruinsalmost works. Indeed, one scene, which reveals the source of what appears to be a ringing mobile phone, sends a healthy chill down the spine. The cast are a classier bunch than you usually encounter in such affairs, and Carter Smith, making his feature debut, directs with an admirable degree of restraint.

The monster proves, however, too vaguely defined to offer a satisfactory threat. Moving significantly faster than non-cognisant plants, but significantly slower than the Mummy, the fiendish tendril could, surely, be evaded by even the laziest and least imaginative of youths.

Mind you, the modern American horror film does rejoice in revealing its heroes to be brainless victims of cannier foreign lunatics and more resourceful overseas plant-life. If Hostel, Paradise Lostand The Ruinsare to be believed, travelling abroad is currently more perilous than it has been at any time since 1945.

DONALD CLARKE