"Here are two spare clips. Don't waste your shells firing at the engine or fuel tank. As a target, it's too small to hit on an aircraft passing overhead at more than fifty miles an hour. Aim for the pilot and the gunner. One good body shot and they'll either crash or head for home."

She took the .45, twisted around in the seat so she was facing backward, flipped off the safety and cocked the hammer. "He's almost on us," she warned Pitt.

"The pilot will roll and come over us slightly off to one side, giving his gunner a clear shot downward," Pitt said coolly. "The instant he lines us up in his sights, shout out which side he's passing, left or right, so I can zigzag under him."

Without questioning Pitt's instructions, Julia gripped the old Colt with both hands, raised the barrel and lined up the sights on the two men perched in front of the wings and engine as it soared down the river. Her face showed more concentration than fear as her finger tightened on the trigger.

"On your left!" she called out.

Pitt threw the runabout in a sharp turn to the left, staying with the ultralight. He heard the quiet staccato burp of an automatic weapon with a suppressor on its muzzle, mingled with the loud thunder of the old Colt, and saw bullets lace the water only three feet alongside the hull as he cut under the ultralight, using its underside to mask the runabout from the gunner's view.

As the ultralight shot ahead, Pitt saw no trace of injury to the pilot or copilot. They looked as if they were enjoying themselves. "You missed!" he snapped.

"I could have sworn I scored," she snapped back furiously.

"Ever hear of a deflection shot?" Pitt lectured her. "You've got to lead a moving target. Haven't you ever hunted ducks?"

"I could never bring myself to shoot a harmless bird," she said loftily as she expertly ejected an empty clip and pumped a full one inside the handgrip of the Colt.

Feminine logic again, thought Pitt. Can't shoot an animal or bird, but not hesitating to blow a man's head off. "If he comes at the same speed and altitude, aim a good ten feet ahead of the pilot."

The ultralight circled around for another attack while its sister craft hung back in the distance. The droning whir of the engine's exhaust echoed off the rock walls of the canyon. The pilot swooped low over the shoreline, the airflow churned out by the propeller blades whipping the tops of the trees along the banks. The serene and picturesque river and the slopes of the forested canyon seemed the wrong location for a life-and-death struggle. The clear green water flowed past banks that were lined with trees marching up the rocky sides of the mountains until they thinned and stopped at the timberline. The yellow aircraft stood out like a colored gemstone, a Mexican fire opal against a sapphire sky. All things considered, Pitt thought fleetingly, there are worse places to die.