10-year-old Harriet dreams of leaving her home, where she doesn't feel she's needed by her mother and sister Gwen. When her mother dies in a car accident, she really starts to make plans for leaving and she finally does …

一个基因科学团队，将新的基因成果——在休眠中的蝎子标本带上了飞机。飞行中在行李舱中的蝎子苏醒，并在飞机上疯狂生长，最后长成杀人的巨蝎。由于巨蝎破坏了线路，飞机也开始出现故障。一场生与死的空中考验就此展开。