The Ruins is an isolate-and-kill horror movie, based on an allegedly thick and depressing novel (unread by me). The ending has been fiddled with, so it does not match the one in print and on the DVD there is yet another alternate ending - though mostly just extended. But it is not so much what happens at the end of the movie that interests me, it's more what happened before the movie even started, since that is still unclear to me (see SPOILERS section down below).
A group of six tourists veer off the beaten path while in Mexico, to visit a Mayan temple. There are two American couples, a Greek and a German who is looking for his brother. As you might guess, some or all of these will end up being toast. When they get to the temple, they are accosted by a man who shouts things at them in a language they don't understand. The man's friends show up and before long, the tourists are driven up the side of the temple, which is now surrounded. Their captives stay away from the structure however. The tourists are not allowed to leave, but they are unsure why. Things take a creepier turn for them as dead bodies are found and ring-tones are not what they seem. Their original, bold assertion that American tourists couldn't possibly just go missing without anybody looking for them, gets weakened as they spend a couple of days and nights on the top of the temple. Some of the group start to fall by the wayside.
The Ruins is not for the squeamish; there is some graphic bloodletting, which looks fairly realistic. The actors play it believable enough for you to want to look away. The slowly building despair and exhaustion are also brought across pretty well, making you feel for the characters, even if they are a bit bland and sometimes make really stupid decisions. The ultimate Evil that is propelling the plot, stays a little ill-defined, but manages to make your skin crawl, even as it borders on being laughably silly. All in all it is a capably done genre-movie that will keep you entertained and grossed out for 90 minutes, even though a fair amount of logical loopholes will not go unnoticed.