Oceania, an underwater seismic survey lab, picks up an unusual phenomenon from the ocean floor: a field of magnetic pulses that drive sharks into a frenzy. Dr. Mike Olsen, his wife Linda, and their crew monitor the incredible convergence of hundreds of sharks around the "energy field." It's unlike anything they've ever seen before. Soon after, divers on a repair mission from Oceania are viciously attacked by the raging sharks and all life-support cables leading to the lab become severed. The oxygen supply is critical and the shark attacks have compromised the stability of the structure. The lab is in danger of collapse.