The Ruins opened on Friday like most horror films, with a single, late Thursday night "promo" screening, to which the press was gamely invited in full knowledge that it would be too late for review, even for any reasonable web deadline. What's different about The Ruins is that it's not a remake or even a copy of any horror film of recent years. We're talking first-class material, adapted from a novel by Scott B. Smith, who wrote both the mesmerizing 1993 book A Simple Plan as well as Sam Raimi's masterful 1998 film of the same name. It's a terrific airplane novel, surprising and gripping, and Dreamworks could have made an outstanding film of it. But they threw it away, perhaps deliberately, hoping for some of that fast opening weekend green, and little caring about making something worthwhile or lasting (like A Simple Plan).

The material is still here, and the director chosen for the job, Carter Smith, can't entirely squelch it (once again Smith wrote his own screenplay). In Smith's novel you hardly notice that the main characters are vapid twenty-somethings on vacation in Mexico, merely because the writer lavishes such good detail in fleshing them out. In the film, we meet the characters quickly and move on to the action. Amy (Jena Malone) and Stacy (Laura Ramsey) are best friends, staying at a resort with their boyfriends, Jeff (Jonathan Tucker) and Eric (Shawn Ashmore), who don't seem to have much in common. They meet Mathias (Joe Anderson), from Germany, who tells them about his brother, who has disappeared with a girl while visiting some secret ancient ruins. He's about to go out there to look for him; would they like to join him? After a night of drinking, dancing and making out, they depart.

The ruins are pretty spectacular; it's like a pyramid with a flat top and steps all around, located in a clearing in the jungle. Vines cover almost every square inch, except a stairway up the middle of one side, and a large clearing at the top. After a few minutes, a band of Mayan sentries show up and prove they mean business by killing one of Mathias's pals. The tourists are not to come down off the ruins. There's a deep pit at the top and they can hear Mathias's brother's cell phone ringing at the bottom of it. Mathias goes down, but falls and breaks his back. Stacy goes down after him and cuts her leg. They realize that they'll have to spend the night and ration food and water. They bicker, and things get progressively worse. (Hint: there's something supernatural at work.) I have a feeling some things were cut out, especially since one of the movie stills shows the characters cavorting in a rainstorm, which never happens.

The main characters are pretty vapid; Jeff is studying to be a doctor and he takes the lead and makes most of the tough decisions. He goes to bed early and seems responsible, but beyond that we don't really know him. Amy and Stacy are differentiated by the fact that Amy is a brunette with glasses and Stacy is a blonde. Amy's big character trait is that she got drunk the night before and started making out with Mathias after Jeff went to bed. The other guys have no real personality other than their clothes and the state of their beards. But not knowing the characters doesn't prevent the movie from growing tense when it's supposed to. Smith's ingenious tale unfolds in just the right layers, with characters making one horrible discovery after another. But each time the movie lurched to a new level, I mourned the fact that it had been tossed off to an amateur director (with only a short film or two to his credit) rather than a proven master of the genre.

Smith directs the movie in a completely rudimentary fashion, straight out of Horror 101. A mean dog jumps out of the back of a truck and "shocks" us. A girl lays in the darkness with her face turned away from the camera; when Stacy reaches for her, the girl's head suddenly turns and jerks into view, hideous and half-decomposed. (Where have I seen that before? Oh yeah. Psycho.) Whenever anything tense happens, Smith's camera begins shaking and wandering everywhere, cutting almost arbitrarily instead of letting it come to rest or discover anything. Now consider that John Carpenter hasn't directed a feature film since 2001, or that Tobe Hooper has trouble getting films financed. The supernatural element of The Ruins also applies directly to the sensibility of David Cronenberg, who is usually concerned with body issues. Not to mention that Wes Craven, George A. Romero, Brian De Palma and John Landis are almost always available these days.

If the studio was merely going to give up on this project, why not spend the same amount of money and effort hiring one of these semi-forgotten masters to do the work? It frankly made me angry thinking of the disdain and contempt they must have had for this project, for the audience and for horror in general. And to make matters worse, The Ruins eventually emerges as an average horror picture, and several steps above every other horror picture released this year. (They even went for an "R" rating, with nudity and liberal use of the "F" word.) And that's without even trying.