At the farmhouse, his closest neighbor was half a mile away. He could sit on his porch at night and hear nothing but the hum of the cicadas and the croaking of frogs. Surprisingly, he’d found the land itself therapeutic. He’d bought the property at a deep discount from an owner who’d allowed it to fall into disrepair, so he spent much of his time working at taming the landscaping or restoring the farmhouse, which needed new everything, from windows to shingles to plumbing. Fisher took comfort in the work—in the ordinariness of it all. Even the briefest of layovers at the farmhouse between missions helped recharge his batteries.

By the time he got home it was near dawn. He threw in a load of laundry, took a shower, checked his e-mail, and stretched out on the couch. He found the remote and turned on the TV. The channel was set to CNN.

“. . . what few initial eyewitness reports we’ve come across talk of dozens of people collapsing where they were standing or slumping over at the dining table. . . .”

Fisher sat bolt upright. He turned up the volume.

“The spokesperson for the governor’s office issued a statement stating that investigators were en route to the small town of Slipstone and that the governor himself would be holding a press conference later this morning. Meanwhile, speculation abounds as to what may be behind the sudden and mysterious deaths in the remote town of Slipstone, New Mexico.”

Fisher felt the hair on the back of his neck stand up. His cell phone started ringing.

HEwas back at Situation Room forty minutes later. Lambert stood at the conference table watching an MSNBC report. Grimsdottir and Redding were seated at workstations on either side of him. In the background Fisher heard the static hiss of radio punctuated by a female voice:

“Slipstone Nine-one-one, please hold . . . Slipstone Nine-one-one, please hold . . . Slipstone Nine-one-one, please hold. . . .”

Lambert looked over his shoulder at Fisher. “Two hundred emergency calls and counting. As far as we can decipher, there are hundreds dead. They’re laying in the streets, in homes, dead at their steering wheels. . . .”

“Good God,” Fisher murmured.

Grimsdottir called, “I’ve got it, Colonel.”

“Put it up.”

The main monitor resolved into a thermal satellite image of what Fisher assumed was Slipstone.

“Give me the overlay, Anna.”

Grimsdottir tapped the keyboard and the image changed to a maze of yellow and orange lines punctuated by circular blooms of red. To Fisher the colors looked eerily familiar. Already guessing the answer, he asked, “What are we seeing, Colonel?”

“Slipstone’s water system.”

“There’re only a few ways that many people can die that quickly: waterborne or airborne.”

His eyes still fixed on the monitor, Lambert nodded grimly. “How long, Anna?”

“Almost there, Colonel.” A few moments later: “Confirmed: it’s the same signature as the Trego.”

Fisher felt like he’d been punched in the stomach. He turned away from the screen and took a deep breath. The Tregohad just been the opening salvo. This was the real event.

Someone had just poisoned an entire American town.

6

NORFOLK NAVAL SHIPYARD, HAMPTON ROADS, VIRGINIA

FISHERangled downward until his depth gauge read thirty feet, then leveled off and checked his OPSAT. He was on track, almost dead center in the middle of the Elizabeth River. A quarter mile to go. His rebreather unit hissed softly in his ears. As it always did, the sound reminded Fisher of a mellower version of Darth Vader.

Displayed across his facemask was a HUD, or Heads-Up Display. Like the display projected onto the windscreen of a modern jet fighter, the faint green overlay on his face mask told him virtually everything he needed to know about his environment, including a map of the river and the shipyard, his current position, the river’s depth and temperature, and distance and bearing to his next waypoint, which showed as a yellow arrow near the upper edge of his mask that changed position and length according to his position. Follow the yellow brick arrow.

Deciding best how to penetrate the shipyard’s Southgate Annex, one of the most secure yards on the Eastern Seaboard, had been the easiest part of his mission. Given the high level of base security, an approach by land was a nonstarter, which had left only one other option: water. This suited Fisher’s preference. His SEAL days had taught him to trust the water. Water was safety; water was camouflage; water was anonymity.

Norfolk Naval Shipyard is one of the busiest in the country, servicing on any given day as much as fifteen percent of the U.S. Navy’s fleet. With seven thousand employees, five hundred acres, and sixty-nine production buildings, the shipyard was an impressive site—more so since it was located eight miles south of the Norfolk Naval Station proper, in the southern branch of the relatively quiet Elizabeth River.

An hour earlier Fisher had parked his car in a wooded parking lot overlooking the eastern bank of the river, and waited until a teenage couple in a steamed-up Ford Escort finished their business and drove off. He’d then retrieved his duffel and walked a few hundred yards through the woods to the shoreline, where he changed into his wet suit, rebreather harness, mask, and fins, then slipped into the water.

Now Fisher craned his head back, checking the surface for boats. It was two A.M. He’d seen virtually no traffic, save for the occasional civilian motor cruiser returning home late after a day of fishing in the Chesapeake. He finned upward and broke the surface, careful to allow only the upper half of his mask to show. To his right, upriver, he could see car headlights crossing the Jordan Bridge, which linked the western and eastern shores.

Directly in front of him, a quarter mile across the water, the shipyard’s Southgate Annex was brightly lit by sodium-vapor lights. Fisher counted ten ships of various sizes, from frigates to refrigerator ships, moored at the piers, and here and there he could see the sparkle of welding torches. A loudspeaker crackled to life and a voice made an annoucement, too distorted for Fisher to hear. As long as the message wasn’t “Intruder in the water,” he didn’t care.

South of the main line of piers was a row of five man-made inlets, each covered by a hangarlike structure fronted by a massive rolling door wide enough to accommodate warships as large as cruisers. These were the annex’s secure docks, or sheds, numbered one through five. The Tregohad been towed into Secure Shed Four, Five being the last in the line.

To reach her, Fisher would have to first have to get past the annex’s sea fence, which stretched some three hundred yards across the entrance to the annex and was marked by a line of blue-lighted buoys, each linked to the next by floating aluminum pipes.

Of course, it wasn’t the fence itself that concerned Fisher, but rather the spotlight-equipped Navy speedboat that constantly patrolled its length.

He picked out a few landmarks he’d chosen from his map before the mission, confirmed their position on his HUD display, then flipped over and dove.

TENminutes later, he stopped swimming and coasted to a stop. He adjusted the compensator on his vest until he was neutrally buoyant, hovering motionless in the water. Aside from the glow of his HUD, he was surrounded by absolute blackness. Night diving could be an exercise in mind control, Fisher knew. Without any external reference points, a vertigo-like confusion can quickly take over. Fisher had seen the bravest of men, divers with hundreds of hours of bottom time, panic while simply floating motionless in dark water. Even he could feel it nipping at the edges of his mind: a primal urge to rush to the surface. He quashed the feeling and focused on his face mask; the soft green glow was reassuring. If his navigation was accurate, the sea fence lay directly ahead.