Sandecker shrugged. "Unfortunately, the present state of the art in containment and cleanup technology and the physical-chemical characteristics of Nerve Agent S are such that once it enters the water very little can be done to ameliorate the penetration. Our only hope is to cut off the source before it releases enough poison to turn the ocean into a cesspool devoin of all life."

"Any lead on where it originates?" asked the President.

"In all probability a ship sunk between Kodiak Island and the Alaskan mainland," replied Sandecker. "Our next step is to backtrace the currents and draw up a search grin."

The President leaned over the coffee table and studied the red circle on the chart for a few moments. Then he gave Sandecker an appraising stare. "As director of NUMA, Admiral, you'll have the dirty job of neutralizing this thing. You have my authority to tap any agency or department of the government with the necessary expertise-the National Science Board, the Army and Coast Guard, the EPA, whoever."

He paused thoughtfully, then asked, "Exactly how potent is Nerve Agent S in seawater?"

Sandecker looked tired, his face drawn. "One teaspoon will kill every living organism in four million gallons of seawater."

"Then we better find it," said the President, a touch of desperation in his voice. "And damned quick!"

DEEP BENEATH THE MURKY WATERS of the James River, off the shoreline of Newport News, Virginia, a pair of divers struggled against the current as they burrowed their way through the muck packed against the rotting hull of the shipwreck.

There was no sense of direction in the black dimensionless liquin.

Visibility was measured in inches as they grimly clutched the pipe of an airlift that sucked up the thick ooze and spit it onto a barge seventy feet above in the sunlight. They labored almost by Braille, their only illumination coming from the feeble glimmer of underwater lights mounted on the edge of the crater they'd slowly excavated over the past several days. All they could see clearly were particles suspended in the water that drifted past their face masks like windswept rain.

It was hard for them to believe there was a world above, sky and clouds and trees bending in a summer breeze. In the nightmare of swirling mud and perpetual darkness it hardly seemed possible that five hundred yards away people and cars moved on the sidewalks and streets of the small city.

There are some people who say you can't sweat underwater, but you can. The divers could feel the sweat forcing its way through the pores of their skin against the protective constriction of their dry suits.

They were beginning to experience the creeping grasp of weariness, yet they had only been on the bottom for eight minutes.