The storm of the decade is forecast to hit the coastal region of Harmony Valley, keeping Park Ranger Chelsea Brennan and Mitch Sanders, a newly appointed marine biologist with the State Park Service busy patrolling the temporarily closed park beaches, especially when dead marine animals begin to wash ashore. To help brace for the storm, Mitch’s wife Ashley goes to her sister’s home at a secluded beachfront community called Shelter Cove. Meanwhile, Sheriff Hoyt Stevens and his deputies will have their hands full keeping the community safe. But high winds and destructive floodwaters are nothing in comparison to the real threat coming as a massive bloom of the deadliest sea creatures on the planet invades Harmony Valley.