The movie is almost satisfactory, not too scary, but interesting. The rappelling and caving however is crap, the cave exploring that is shown in the movie is totally wrong. The gear, the techniques are absolutely unreal. Where did all the light in the cave come from? They are supposed to be 5 km deep in the cavern. There should be no light whatsoever, except for their flashlights. They didn't have any safety precautions, no spare batteries for headlamps. They didn't even have appropriate clothes. It is very cold in a cave so deep, about 5 Celcius or less, you need thermo suits, lots of food, fuel and other stuff. They were wearing t-shirts. An expedition into a deep cave lasts weeks not hours. They had enough rope maybe for 200 - 300 hundred meters. They didn't make any anchoring. You just can't hold a rope while somebody is descending, it has to be anchored. When one descends on a rappel he has to descend slowly and gradually. At the speed as shown in the movie you burn the rope, burn your fingers when you touch the metal parts of your gear. Don't try this at home boys and girls, you'll get killed.