A couple of American gals are biking through Argentina, have a little argument, temporarily part ways, then one goes missing. The other tries to find her. A cast mostly of little-knowns, except Karl Urban. Yes the gals have been in a few other flicks, even a few I've seen, but I didn't recognize 'em.
As a thriller/horror flick it's really more thriller. It is a remake of a 1970 UK thriller of the same title, but I've not seen that so I can't compare the two.
The flick is kindof slow paced up front, though it eventually did pick up some. Despite the sluggishness at first the movie did do a decent job of drawing the viewer in - you know, like getting the viewer to scold the girls when they do something stupid that is sure to lead to their demise. Once invested one is compelled to watch it play out.
Shot in some really good locations - nice picks by the crew for some very interesting scenery. No glaring complaints about the performances. A decent average-good thriller that doesn't have to resort to a lot of blood or gore or a bunch of improbable/impossible series of events. Doesn't even encroach on torture porn horror (like Saw or Hostel or Touristas) even though they could have punted and taken it that direction. I doubt it'll spawn any nightmares. It isn't groundbreaking, the story might seem familiar, but it isn't terrible either. It would make a decent friday-night popcorn thriller if you're stuck for deciding what to watch and don't want to get into anything too graphic.