Two sisters vacationing in Mexico are trapped in a shark cage at the bottom of the ocean. With less than an hour of oxygen left and great white sharks circling nearby, they must fight to survive.

The strangers: A couple staying at an isolated vacation home, returns from a wedding reception. They receive a knock on the door in the middle of the night. What ensues is a violent invasion by three strangers, their faces hidden behind masks. As the night goes on, the reality of their psychological terror becomes more terrifying than anything both could have imagined. Now, they must go beyond what either of them thought they were capable of in order...