The calmer you are, the less air you lose.

It seemed to be just a perfect day for a dive. Clear sight, stable weather and an incredible, reclusive spot. Drew and May, two sisters that share a close and complex bond, are excited: both experienced, adventurous divers marvel at this underwater world. During their dive, May is abruptly hit by a rock, leaving her shaken but luckily with only a small scratch. But the sisters relief is short-lived: the rock came from a landslide above water. Suddenly, countless rocks are cascading into the ocean. May gets struck by the rockfall and falls down, into the deep. Lying 28 meters below, she is trapped by debris, unable to move. With dangerously low levels of oxygen and cold temperatures, it is up to Drew to fight for her sisters life. A frantic race for survival ensues as Drew desperately fights to find help in the isolated landscape, whilst May is pinned to the bottom of the ocean, facing her own psychological battle as she confronts the devastating reality. Drew uses all her ingenuity, resourcefulness, and fortitude to try and keep her sister from imminent death. Drew must put her own life in jeopardy and risk paying the ultimate sacrifice. Time is running out.