"I'd better call the INS field agents again and alert them to the fact that we've left the area and give them our destination."

"A good idea," said Pitt, pushing the throttle forward to its stop with one hand while handing her the phone with the other. "They can concentrate their forces on the retreat instead of worrying about us at the cabin."

"Did you hear from your NUMA people?" Julia shouted above the increased roar of the exhaust.

"They're supposed to meet and pick me up after we reach Grapevine Bay."

"Do they use little open aircraft painted yellow?"

He shook his head. "NUMA leases executive jets and helicopters with turquoise color schemes. Why do you ask?"

Julia tapped Pitt on the shoulder and pointed over the stern at a yellow ultralight that was chasing them down the river. "If they're not friends, they must be foes."

PlTT TOOK A FAST LOOK OVER HIS SHOULDER AT THE AIRCRAFT rapidly closing over the wake of the Chris-Craft. He recognized it as an ultra-light, a pusher-engined, high-winged monoplane with tricycle landing gear and tandem seats for two people. The pilot sat forward, out in the open, with his passenger behind and slightly elevated. The airframe consisted of aluminum tubing braced with thin cable. Propelled by a lightweight, reduction-drive, fifty-horsepower engine, it could move fast. Pitt guessed it was capable of 120 miles an hour.

The pilot was flying directly over the middle of the river no more than forty feet off the water. He was good, Pitt admitted. The air currents swirled through the narrow canyon in a series of strong wind gusts, but the pilot compensated and kept the ultralight on a straight and level course. He was coming after the runabout intentionally and purposefully, like someone who knew exactly what he was about to do. There was no hesitation and no uncertainty about who was going to end up the loser in the coming unequal contest. God knows Pitt had no doubts, not when he saw a man strapped in the seat behind the pilot holding a stubby machine pistol in his hands.

"Force everyone to get down as low as they can," Pitt ordered Julia.

She spoke in Chinese, passing on Pitt's command, but the runabout's passengers were already so overcrowded in the small cockpits they had no place to go. All they could do was settle as low as humanly possible in the leather seats and duck their heads.

"Oh, dear lord," gasped Julia. "There are two more of them about a mile behind the first."

"I wish you hadn't told me," said Pitt, hunched over the steering wheel, willing the runabout to go faster. "They're not about to let us escape and spread the gospel about their shady operation."