As a tsunami approaches, the Wilmington, N.C., area is evacuated, and Miles and his family join the exodus. Meanwhile, Laura searches for Rich, who has been arrested and is being held in an underground facility.

Hoping to learn more about the creatures and the experiments behind them, Rich and Laura hunt down the mysterious Davis Lee for answers. But encountering Lee brings out a dark and violent side to Rich. Meanwhile, Miles---now a pariah at school because of his bizarre behavior---retaliates when he's attacked by a smug bully.

Rich comes to Laura's rescue when she is drugged and left in a field after discovering the truth about the deadly species' origin. The pair then go on a mission to track down the scientists behind the creatures' creation. Elsewhere, Miles joins a group of aquarium workers on a boat trip to find the unhatched eggs.

Lee and his agents pursue Laura and Rich. While in hiding, Laura communicates with a mysterious stranger who may know something about the creatures. Elsewhere, Miles and Caitlin go to a late-night beach party that turns tragic.

Rich and Laura escape from the hospital with footage of the creatures and plan to show it to a news station. Meanwhile, Miles has all but given up hope that Nimrod is alive.

After resurfacing from their trip to the ocean floor, Laura and Rich discover that their boat has disappeared. Meanwhile, Miles becomes ill in class and Savannah thinks that Nimrod may have something to do with it.

As Laura and Rich struggle in their submersible, they're horrified to discover that the mysterious species is laying thousands of eggs underwater. Meanwhile, Miles suspects Nimrod is to blame for a vicious attack on the docks.

Laura, Rich and Jackson try to use the submersible device they built to investigate the spawning site. But when Rich and Laura begin to descend, they experience technical difficulties that endanger their lives. Elsewhere, Miles does volunteer work at an aquarium.

A cover-up imperils Laura, hiding out with Rich in a California cove, where she makes disturbing finds on the creatures from Cirko's files. Elsewhere, a frantic Miles flees with Nim in a getaway that embattles him with cops and forces him to make an emotional decision.

Cover-up rogues imperil Laura and Rich, who are dogged by assassins while seeking evidence of the predatory sea creatures. Also: Niles goes to great lengths to protect Nim, whose discovery has serious ramifications with Niles' parents.

U.S. waters draw a creature, tracked by Rich and Laura via a GPS device to a California waterway, where a monster surfaces---to the astonishment of locals and tourists. Meanwhile, Nimrod gets loose in a large grocery store; and Laura faces Cirko's scrutiny.

A sea hunt obsesses Laura in a quest for the creature that enlists the aid of an adventurer and old flame, who confront the monstrous species in the ocean. Back on land, Miles' baby version of the creature creates havoc.

Sea creatures cause disaster on a Texas lake; Laura runs afoul of the government in her probe; Rich suffers from debilitating flashbacks; Cirko makes a startling discovery that links the beings to global warming; and Miles continues to tend to a baby creature.

A sea-creature hunt bonds Laura and Rich, who link up on an isle where a beast is beached. Elsewhere, the baby critter found by Miles wreaks havoc in suburbia; and a deceased creature still poses a threat to a team performing an autopsy.

Sea mysteries surface in the series opener, spun around a bold marine biologist who has a terrifying underwater encounter with strange creatures. So does an inquisitive teen from California and a Louisiana scuba diver, whose confrontation has a deadly outcome.