Everyone at Florida's Sea World is so excited about the newly open "Undersea Kingdom," a maze of underwater plexiglass tunnels that allows visitors to get closer to ocean life than ever before... until one uninvited baby shark incidentally gets lost in the park's lagoon through a faulty sea gate and eventually dies. The young shark's 35-foot mother quickly follows her baby, and put the water and people of Sea World into the most horrible deadly nightmare they've never ever imagined before.