PREVIEW: Deep Blue Sea

n a remote underwater facility, doctors Susan McCallister and Jim Whitlock are conducting research on mako sharks to help in the re-activation of dormant human brain cells like those found in Alzheimer's disease patients. After one of the sharks escapes the facility and attempts to attack a boat full of young adults, financial backers send corporate executive Russell Franklin to investigate the facility.

Susan and Jim prove their research is working by testing a certain protein complex that was removed from the brain tissue of their largest shark, which bites off Jim's right arm upon awakening in the laboratory. Brenda Kerns, the tower's operator, calls a helicopter that braves through heavy rain and strong winds to evacuate Jim. As Jim is being lifted the cable jams, dropping Jim and his stretcher into the shark pen. The largest shark grabs the stretcher and pulls the helicopter into the tower, killing Brenda and the pilots, as well as causing massive explosions that severely damage the facility.

In the laboratory, Susan, Franklin, wrangler Carter Blake, marine biologist Janice Higgins, and engineer Tom Scoggins witness the shark smash the stretcher against the laboratory's main window, which then shatters, drowning Jim and flooding the facility. The group goes to the facility's wet entry, where they plan to take a submersible to escape to the surface. Susan confesses to the others that she and Jim genetically engineered the sharks to increase their brain size, as they were not naturally large enough to harvest sufficient amounts of the protein complex; this broke protocol and made the sharks smarter and deadlier. In the facility's partially flooded kitchen, cook Sherman "Preacher" Dudley, manages to kill a strayed shark by setting off an explosion with his lighter.

When the group reaches the wet entry, they discover that the submersible has been damaged and is unsuitable for use. While delivering a monologue emphasizing the need for group unity, Franklin is dragged into the submersible pool by the largest shark and devoured. The remaining crew opt to climb up the elevator shaft at the risk of destabilizing the pool. As they climb, explosive tremors cause the ladder to break, and Janice loses her grip and falls into the water. Despite Carter's attempt to save her, a shark drags Janice under and devours her.

The rest of the group moves on, encountering Preacher. Carter and Scoggins go to the flooded laboratory to activate a control panel that drains a stairway to the surface, while Susan heads to her room to collect her research material. Carter and Scoggins reach the control panel, but the largest shark storms in, ripping Scoggins apart and damaging the controls. In her room, Susan encounters another shark and electrocutes it with a power cable, destroying her research in the process.

After regrouping, Carter, Susan, and Preacher go to a decompression chamber and swim to the surface while using oxygen tanks to bait the last shark as it attacks. Upon reaching the surface, Preacher is grabbed by the shark, suffering injuries to his leg, but he is released when he stabs the shark in the eye with his crucifix. Carter realizes that the sharks have been using them to flood the facility so that they can ram their way through the fences at the surface.

To keep the shark from escaping to the open sea, Susan deliberately cuts her hand and dives into the water. Although she manages to distract the shark with her blood, she is unable to get out of the water and is devoured, despite Carter's efforts to save her. While Carter is holding the shark's dorsal fin, Preacher shoots the shark with a harpoon but also pierces Carter's thigh. Carter orders Preacher to connect the trailing wire to a battery, sending an electric current to an explosive charge in the harpoon, killing the shark in spectacular fashion. Carter manages to free himself just in time after the shark manages to breach through the fence right before it gets blown. He resurfaces and swims to shore, reuniting with Preacher. Moments later, they see a boat approaching the sinking facility.