fast from beneath him. The hair-trigger Iranian government had wasted no time in scrambling its air defense. He brought the Sovereign around, caught a visual fix. What the Iranians had sent to intercept him were a pair of Chinese-built J-6s, reverse-engineered copies of the old MiG-19 used in the mid-1950s. These jets were so out of date, the Chengdu plant had stopped manufacturing them more than a decade ago. Even so, they were armed and the Sovereign wasn't. He needed to do something to negate that enormous advantage.
They'd expect him to turn tail and run. Instead he lowered the Sovereign's nose and put on a burst of speed as he headed directly toward them. Clearly startled, the Iranian pilots did nothing until the last moment, when they each peeled away from the Sovereign's path.
As soon as they'd done so, Bourne pulled back on the yoke and brought the Sovereign's nose to the vertical, performing a loop that set him behind both of them. They turned, describing paths like cloverleafs, homing in on him from either side.
They began to fire at him. He dipped below the crossfire, and it ceased immediately. Choosing the J-6 on the right because it was slightly closer, he banked sharply toward it. He allowed it to come under him, allowed the pilot to assume he'd made a tactical error. Taking evasive maneuvers as the chatter of the machine gun sprang up again, he waited until the J-6 had locked on to his tail, then he tipped the Sovereign's nose up again. The Iranian pilot had seen the maneuver before and was ready, climbing steeply just behind the Sovereign. He knew what Bourne would do next: put the Sovereign into a steep dive. This Bourne did, but he also banked sharply to the right. The J-6 followed, even as Bourne punched in every ounce of the Sovereign's speed. The plane began to chatter in the powerful shearing force. Bourne steepened both the bank and the dive.
Behind him, the old J-6 was shuddering and jerking. All at once a handful of rivets were sucked off the left wing. The wing crumpled as if punched by an invisible fist. The wing ripped from its socket in the fuselage. The two sections of the J-6 blew apart in a welter of stripped and shredded metal, plummeting end-over-end downward to the earth.
Bullets ripped through the Sovereign's skin as the second J-6 came after them. Now Bourne lit out for the border to Afghanistan, crossing it within seconds. The second Iranian J-6, undeterred, came on, its engines screaming, its guns chattering.
Just south of the position where he had crossed into Afghani airspace was a chain of mountains that began in northern Iran. The mountains didn't rise to significant height, however, until they reached Bourne's current position, just northwest of Koh-i-Markhura. With a compass heading of east by southeast, he dipped the Sovereign toward the highest peaks.
The J-6 was shuddering and shrieking as it flattened out the curve of its descent. Having seen what had happened to his companion, the Iranian pilot had no intention of getting that close to the Sovereign. But it shadowed Bourne's plane, dogging it from behind and just above, now and again firing short bursts at his engines.
Bourne could see that the pilot was trying to herd him into a narrow valley between two sharp-edged mountains that loomed ahead. In the confined space, the pilot sought to keep the Sovereign's superior maneuverability to a minimum, catch it in the chute, and shoot it down.
The mountains rose up, blocking out light on either side. The massive rock faces blurred by. Both planes were in the chute now. The Iranian pilot had the Sovereign just where he wanted it. He began to fire in earnest, knowing that his prey was limited in the evasive maneuvers it could take.
Bourne felt several more hits judder through the Sovereign. If the J-6 hit an engine, he was finished. The end would come before he had a chance to react. Turning the plane on its right wingtip, he waggled out of the line of fire. But the maneuver would help him only temporarily. Unless he could find a more permanent solution, the J-6 would shoot him out of the sky.
Off to his left he saw a jagged rift in the sheer mountain wall, and immediately headed for it. Almost at once he saw the danger: a spire of rock splitting the aperture in two.
The defile they were in was now so narrow that behind