the movie be almost satisfactory and not too scary and but interesting . the rappelling and cave however be crap and the cave explore that be show in the movie be totally wrong . the gear and the technique be absolutely unreal . where do all the light in the cave come from . they be suppose to be 5 km deep in the cavern . there should be no light whatsoever and except for their flashlight . they do not have any safety precaution and no spare battery for headlamp . they do not even have appropriate clothes . it be very cold in a cave so deep and about 5 celcius or less and you need thermo suit and lot of food and fuel and other stuff . they be wear t shirt . an expedition into a deep cave last week not hour . they have enough rope maybe for 200 300 hundred meter . they do not make any anchoring . you just can not hold a rope while somebody be descend and it have to be anchor . when one descend on a rappel he have to descend slowly and gradually . at the speed a show in the movie you burn the rope and burn your finger when you touch the metal part of your gear . don not try this at home boy and girl and you will get kill .