The sisters May and Drew learned to dive since they were children taught by their father. Presently May is working diving at an oil platform and Drew has just lost her job. They decide to go on vacation to a remote area to dive and explore caves. They do not pay attention in the warning that the area is subject to collapse of rocks and suddenly, there are many falling rocks and Amy is stuck by a rock thirty meters below sea level. The clumsy and nervous Drew has to bring air cylinders and the car jack to release her sister, but their plan fails. What will happen to Amy?