After a mysterious animal carcass is discovered on the shore of Sullivan's Island, Laura and Rich head there to look for some answers but instead get detained for questioning. Also, a team of scientists face a hazardous autopsy of the deceased creature. Meanwhile, Miles decides to name his new discovery Nimrod but faces panic and trouble when Savannah throws a party at which point Nimrod ends up escaping.

Laura and Jackson head out to sea where she ends up using a GPS device to track one of the creatures. Rich finds proof that the sinkholes in his visions are real causing him to continue obsessing over his brother's death. Meanwhile, Lee tries to talk Cirko out of telling the Pentagon that the new species should be considered extremely dangerous.

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.

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.

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.