As a massive tsunami heads for the east coast, Laura must save Rich by heading to North Carolina where Miles and his family are trying to escape with their lives.
Laura and Rich decide that it's time to get some answers from Lee as Laura considers going back home. Meanwhile, Miles gets in trouble with the local residents after a violent incident with a bully.
The search for the mysterious force responsible for the creatures leads Laura and Rich to an abandoned lab. Meanwhile, Miles joins the aquarium crew in searching for the field of unhatched eggs.
On the run with Rich, Laura encounters a mysterious person who claims to know the origin of the creatures. Meanwhile, Miles fears the worst when two of Caitlin's friends vanish at the beach.
Rich and Laura try to get the footage of their trip to the ocean bottom to a news station before Lee can stop them. Meanwhile, Miles must watch as doctors prepare Nim for an autopsy.
Laura and Rich are in for another shock when they leave the ocean floor and return to the surface. Meanwhile, Savannah suspects that Nimrod's responsible for Miles ending up in the hospital.
Trapped in the submersible, Laura fears survival is impossible while Rich begins to hallucinate. Miles worries about Nimrod when he hears of trouble at the marine docks. Phil helps Miles look for Nimrod but they discover something else.
Jackson helps Laura and Rich build a submersible so that they can visit a site where the creatures spawn. Meanwhile, the Bennett's consider boot camp as a way to discipline Miles.