挪威的一次冬季潜水之旅变成了两姐妹的惊魂之旅,在潜水过程中其中一人被落石困在了海底,此时必须与时间赛跑,因为氧气在悄悄的流失。The Swedish/Norwegian half sisters are doing their yearly winter diving in northern Norway. An accident occurs and a rock traps Tuva against the sea bottom 30 meters down. Ida's abilities to handle a crisis are tested hard. On their own without help from the outer world are the sisters forced to rescue themselves.