They are known to be one of the loudest organisms in the sea. They can generate acoustic pressures up to twelve PSI. The snap from their claws is so powerful, they can produce flashes of light. Normally, they are harmless, for they grow no larger than two inches in length. But these are not normal circumstances. In the waters of Lilly May, Florida, something has gone horribly wrong. The police department gets flooded with reports of heavy sound waves and flashing under the water; the remains of a thirty-eight-foot whale shark wash ashore, and a derelict boat is found adrift, its deck covered in blood. Assisting with the police investigation, marine biologist Jason Rose works diligently to uncover the cause of the phenomenon. The readings from offshore acoustic buoys reveal the occurrence of brief but intense soundwaves—like pistol shots under the water. The truth reveals itself by escalating the horror to mass murder. A colony of giant pistol shrimp, grotesquely mutated from toxic exposure, have invaded the Florida coast. Their snapping claws are capable of producing intense heat and thunderous shockwaves. Like a swarm of locusts, they will stop at nothing to devour anything inhabiting the water.