The mystery ensnares marine biologist Laura Daughtery in California, and family man Richard Connelly fishing in the Gulf of Mexico. Meanwhile, in North Carolina, teenager Miles Bennett finds one of the creature's eggs.

Miles tries to form a bond with the new species; Laura and Rich try to get onto Sullivan's Island to learn about the mysterious carcass that washed ashore.

Lee and Cirko begin to theorize that the unidentified species is causing global warming by digging beneath the ocean bed.

When Daughtery and Jackson encounter one of the unidentified species at sea, Daughtery fires a GPS tracking device into it in an effort to track it.

Animal control officers question good friends Miles and Phil, the keepers of Nimrod, when a neighbour's dog is reported missing.

Cirko discerns the origin of the creatures while studying a sea orchid; when Laura returns home, she finds that her house has been ransacked by the government.