Ella is suddenly hit from below by an aggressive 600-pound sea lion. The sea lion knocks out her teeth and bites her neck a millimeter from her carotid artery. Then, Haley is stung by the tiny Irukandji jellyfish. Within seconds, she begins suffering from excruciating pain. Time is ticking as Haley fights for her life. Finally, Dean is excited to try his brand new spearfishing gear on a remote spot in South Australia. Soon, a huge force pulls him under as a shark is approaching. Will he live?