The film focuses on four Americans who go to South America on vacation at a resort and get drunk a lot. You've got the overly serious boyfriend Jeff (Jonathan Tucker), who doesn't pay attention to his flirtatious girlfriend Amy (Jena Malone, in her most conventional role, the blonde Stacy (Laura Ramsey) and her nice, comical boyfriend Eric (Shawn Ashmore).

An interesting thing to note is how once things start going bad there is a role reversal for the two female characters. Amy goes from seeming weak to capable and determined while Stacy goes from seeming in control to losing it in a big way. I always thought it was interesting how all of the doubts expressed by Amy about their actions ultimately prove well founded. Though, she does have a few moments of questionable action, such as begging the villagers who keep the group imprisoned at the aforementioned ruins for help despite the fact they don't speak English and had just shot one of their fellow travelers (a Greek tourist).

For the most part, the vine effects in this film were well done. The flowers making noise effect seemed a little farfetched, but no more than a vine being able to move quickly and strangle someone. It's nice to see a movie that doesn't feel the need to explain its creature's origin (ala Cloverfield, though that film certainly hinted at a few possibilities), but rather deal with the immediate emotional fall out experienced by the protagonists.

It was also nice to see a film where the main characters make hasty decisions and wind up making things worse. I started to root for the villagers more than the main characters, because they seemed to be the only ones with the greater good in mind. Did any of them stop and think what could happen if they escaped and spread this strange plant? The requisite Hollywood required ending where someone survives could've at least had the decency to hint at exploring this possibility, but sadly we don't even get a brief scene after the credits.