Carla's sister accidetally falls off a cliff when the railing becomes loose while Carla's boyfriend takes photos. She has a hard time getting over her death and keeps having visions of her sister yelling at her for not saving her. It seems that everytime she gets next to a edge of a high area, she gets terrified. She then starts to take a class with other Acrophobiacs. Then the people in the group start getting killed one by one. She starts to suspect that someone wants her never to get over her fear and that the loose railing was meant for her. 　　译文(2): 当卡拉的男朋友拍照时，栏杆松动了，卡拉的妹妹意外地从悬崖上掉了下去。她很难从死亡的阴影中走出来一直幻想着她姐姐因为没有救她而对她大喊大叫。似乎每次她靠近高处的边缘，她都会感到害怕。然后她开始和其他恐高症患者一起上课。然后组里的人开始一个接一个地被杀。她开始怀疑有人想让她永远无法克服自己的恐惧，而松动的栏杆是为她准备的。