As a brilliant designer of undersea craft for the National Underwater and Marine Agency, Zavala ordinarily carried nothing more lethal than a laptop computer. But his years working for NUMA’s Special Assignments Team had taught him the wisdom of the Boy Scout adage to be prepared. Zavala reached under the car seat, his fingers closed on a quick-release holster, and his hand came out with a Walther PPK handgun.

He got out of the car and made his way around the boathouse, moving with the stealth of a deer hunter. Pressing his back to the exterior wall, he edged his way to the corner and popped out into the open, gun extended with both hands and ready to find a target.

A broad-shouldered man dressed in tan shorts and white T-shirt was standing on the riverbank with his back to Zavala. The man held a pistol down by his thigh and was inspecting a paper bull’s-eye pinned to a tree. A cloud of purple smoke hung in the air. The man slipped a pair of ear protectors off his head just as Zavala stepped on a twig. He turned at the snapping sound and saw Zavala creeping around the corner with the gun clutched in his hands.

Kurt Austin, Zavala’s boss on NUMA’s Special Assignments Team, grinned and said, “Going on a turkey shoot, Joe?”

Zavala lowered the gun and walked over to the tree to inspect the hole that had been punched slightly off the center ring of the target.

“You’re the one who should be hunting turkeys, deadeye.”

Austin removed his yellow protective shooting goggles to reveal blue eyes the color of coral under water. “I’ll stick to stationary targets for now.” He glanced at Zavala’s pistol. “What’s with the SWAT team imitation?”

Zavala tucked the gun into his belt. “You didn’t tell me you’d turned your expensive riverfront property into a shooting gallery.”

Austin blew the smoke away from the pistol barrel like a gun-fighter who’d beaten his opponent to the draw.

“I couldn’t wait to try out my new toy at a shooting range.”

He handed the flintlock dueling pistol to Zavala, who inspected the walnut stock and the engraved octagonal barrel.

“Nice balance,” he said, hefting the weapon. “How old is it?”

“It was made in 1785 by Robert Wogdon, a London gunsmith. He fashioned some of the most accurate dueling pistols of his day. You test a dueling pistol by dangling it down at arm’s length. Then you bring it up quickly and hold it just long enough to check the sights and squeeze off a shot. It should be right on target.”

Zavala aimed for another tree and clicked his tongue to simulate gunfire.

“Bull’s-eye,” Austin said.

Zavala handed the pistol back. “Didn’t you tell me your pistol collection was complete?”

“Blame it on Rudi,” Austin said with a shrug. Rudi Gunn was the assistant director of NUMA.