The movie went from a 7 down to a 3 then to a 1 towards the end. First of all, how can the closest friend and colleague of her Adam cannot retrace the path to her work site (as she even able to go back to retrieve her bag). 2nd, as soon as the rain started to fall, it is just illogical that there's no sign of desperate attempt to quench her thirst or trying to fill up the empty bottle from cascading water. And third and most absurd of all, she were able to survive long enough under the water as the hole filled up to the brim. In fact is more logical if she is able to float and cling on the wall of the hole as the water rises. The movie just try to be beautiful and majestic but failed in the logic - that spoilt it all.