Not terrible, but...
... WAY wasted potential.
This movie could have been good, maybe even great, if it just weren't for all the plot holes, illogical inaccurasies, uneven dialogue, Thandie Newton (she was bad in this movie) , non-explanation of the main mystery, dumb character decisions and worst of all, the ending.
I don't blame Brad Anderson, he still did a great job directing this movie. But the script could need a whole lot of improvement.