It's nearing the end of the Mexican vacation for best friends Amy (Jena Malone) and Stacy (Laura Ramsey), who have brought their boyfriends Jeff (Jonathan Tucker) and Eric (Shawn Ashmore) along with them for much sunbathing during the day, and partying at night. Today they are relaxing by the hotel pool when Amy notices she has lost an earring and makes a fuss about finding it until a German tourist called Mathias (Joe Anderson) walks over with said object. A grateful Amy invites him to share a drink with them, and he tells them of his plans to visit some Mayan ruins tomorrow - if they tagged along it would make a change from sunning themselves, wouldn't it?
Scott Smith streamlined his horror novel of the same name for the big screen in his adaptation of The Ruins, and while the premise was the same, the film was expressly designed to catch those familiar with the source off guard, which could be seen as wrongfooting the fans - not really behaviour that could endear the film to them. What he did manage to capture was the relentless quality of the dread, but the unusual "monster" came across as slightly daft when translated into a cinematic form, proving that what may be effective on the page may not be quite as daunting elsewhere when the task would be to have us watch the plot unfold rather than envisage it in our heads.
But enough of the book, did the movie stand up on its own two feet as its own entity? It does fall into the clichés of tourist trap chillers, and if the plotting was not so fresh - this could easily be The Texas Chain Saw Massacre with killer plants - at least director Carter Smith worked up a degree of tension that made you wonder who would survive and what would be left of them, to coin a phrase. The party of five who venture out to the middle of nowhere, ostensibly to meet up with Mathias' brother, are far more vulnerable than they realise for being so far off the beaten track, nothing especially original there, it was the premise for many a backwoods shocker after all.
Which naturally means for a twenty-first century horror movie that they can't get a signal on their phones, yes, they're really that isolated. They finally reach the ruins after some trekking, and while the ancient pyramid they find is impressive though overgrown, they have not counted on the natives being less than friendly. In fact, no sooner have they arrived that a selection of modern day Mayans have appeared from the undergrowth brandishing guns and bows, and when Amy backs into a patch of plantlife, they go nuts and refuse to let them leave. Thus the tourists are stranded at the top of the pyramid faced with quite a conundrum even more perilous than it initially appears.
Mathias seems certain that his mates will arrive tomorrow, but medical student Jeff is not so sure and starts making like a dedicated survivalist, saving water and drawing up plans for a long stay. Then from the pit in the roof of the pyramid they hear a ringtone... What most satisfies about The Ruins is that there's absolutely no jokiness, no winking at the audience that this is a bit of fun, and as a result the dilemma is tangibly desperate. Yet no matter how it is dressed up, this was basically slasher movie territory we are dealing with here, complete with final girl after the characters were being picked off one by one by the bizarre vegetation that has a few tricks to play to ensure it has its fill of holidaymakers. It feels bleak, but as the ending illustrates it could have been even grimmer, faltering a little at the finale as if the hard edged cruelty had been too much, and the book's bleak climax was consciously backed away from. Music by Graeme Revell.