'The bullet that you'll find in that tree will lead you to my killer,' he said. 'Retrieve it and look for traces of Rubidium-82.'

'We found that compound on the bullets that killed your wife and daughter,' Ethan said.

'And you'll find it on all ammunition used by personnel at IRIS,' Purcell said. 'I took the liberty of dousing all of their weapons and ammunition in the armory before I fled.'

'What armory? And how do we find the black hole that IRIS is using?' Lopez asked.

'Wait for the earthquake,' Purcell said, 'at precisely sixteen-seventeen hundred hours and twelve seconds this afternoon, off the coast of the Dominican Republic. Search for electromagnetic anomalies in the Bermuda Triangle at the same time. You'll find IRIS there.'

'There must be another way,' Ethan pleaded. 'Some other path that will still ensure justice for your family.'

'That's not a chance I'm willing to take,' Purcell said. 'Katherine Abell is innocent of any crime. She may be able to help you bring him to justice, if you can prove to her that he is behind all that has happened, and that it is better to oppose him than stand with him.'

'She's devoted to him, it's no use,' Lopez replied. 'We need you, Charles.'

Purcell checked his watch again and then suddenly stood up straight and lifted his chin. He wiped the rest of the tears from his face. There was a terminal determination in his eyes.

'Good luck, both of you,' he said. 'Find the man who killed my family.'

Lopez shook her head and leapt forward. 'No!'

Ethan opened his mouth to speak but a sharp crack split the air around him.

Lopez slammed into Purcell, the pair of them spinning sideways in a gruesome pirouette. As if in slow motion, Purcell shuddered as a bullet slammed into his side and a fine mist of crimson spray exploded from his shirt as the projectile smashed through his chest cavity and exited from between his ribs. The scientist's body went limp as it fell, Lopez rolling with him through the air as they plunged down onto the soft sand.

Ethan saw the tree that Purcell had indicated shudder as a spray of bark fell from its trunk and the bullet buried itself in the wood. He leapt forward, hurling himself down on the sand alongside Purcell as Lopez grabbed his face in desperation, her other hand pressed against the exit wound spilling bright blood across his white shirt.

'Stay with me, Charles!' she shouted. 'Don't goddamn quit now! Where are those documents?'

Purcell looked at her as Ethan watched, his eyes hooded and his expression sagging as he whispered. 'My father took his secrets to the grave, as shall I,' he murmured. 'Time will tell, Nicola.'

Ethan felt his heart sink as Purcell gasped, and then the life in his eyes was extinguished like a distant dying star.

A burst of automatic fire raked the bushes around them, and Ethan grabbed Lopez by the arm.

'He's gone!' he shouted. 'Fall back!'

42.

Ethan hit the ground and rolled into a dense thicket of reeds as a lethal hail of automatic fire blasted the edge of the forest. He saw Lopez hurl herself down behind a tree trunk, covering her face as chips of bark showered down across the foliage around her.

The shooting stopped, the Everglades silent in the heat again as leaves and bark chips dislodged by bullets drifted down around Ethan. He squinted through the reeds and saw Purcell lying on the sand, the side of his chest a bloody mess, and he felt a crushing melancholy for the man's tragic sacrifice. Then he saw the camera pinned beneath the scientist's body.

'We've got to get that camera!' Ethan whispered to Lopez.

'Where the hell's Bryson?' she asked in reply.

Ethan aimed his rifle through the reeds, searching for muzzle flash or signs of movement. He was expecting another broadside of gunfire, not the pair of grenades that thumped down onto the sand barely ten feet from where he lay.

'Grenades!'

Ethan leapt to his feet with Lopez and they both sprinted away from the spit of land as another hail of automatic fire swept the forest around them. Ethan hurled himself down into the bushes alongside Lopez and threw one arm over his head and the other over her as he waited for the grenades to explode.

Two feeble pops crackled on the hot air around them, and Ethan turned to see thick clouds of smoke billowing out through the dense undergrowth, as bullets whipped through the forest around them.

'They're coming ashore!' Lopez shouted.

Ethan cursed as he heard the sound of another airboat engine somewhere in front of them beyond the billowing wall of smoke. He could see no more than Lopez, and their attacker was so close that he could not shoot for fear of hitting the precious camera. More bullets flew past, mostly above their heads, and he realized that whoever had come ashore was firing only to keep their heads down.

'Damn it, we need to cut them off. Where the hell is Bryson?'

The choking smoke curled around them, stinging Ethan's eyes as he tried to see through the gloom. Another rattling volley of gunfire zipped and popped through the branches above their heads, and then Ethan heard the sound of the airboat's engine roar and glimpsed through the trees to his right the craft thunder past, the tall man with blond hair at the wheel.

Ethan leapt to his feet. 'Let's move!'

Lopez followed him at a run as they leapt fallen trees and pools of stagnant water until they burst out of the forest to see the airboat accelerating away. Ethan dropped down onto one knee and raised the M-16, selected single-shot and using the telescopic sight to aim not for the helmsman but for the much larger target of the engine. Ethan squeezed the trigger and the rifle jolted into his shoulder. Five shots cracked out as he fired one after the other and was rewarded with a puff of white smoke that spiraled from somewhere within the engine block.

A second airboat soared into view, swerving around the corner of the island and racing toward them. Ethan could see Bryson at the wheel as he guided the airboat in alongside the shore.

'The hell happened to you?' Lopez shouted at him.

Bryson's face was flushed with a mixture of anger and embarrassment as he looked at her.

'He snuck up on me, God knows how.'

Ethan scowled at Bryson. 'I thought you were a professional!'

'And I thought you told me Purcell was alone,' Bryson shot back.

Ethan cursed and looked over his shoulder at the spit of land where Charles Purcell had died. The camera had vanished.

'We can still get the bullet Purcell mentioned,' Lopez suggested.

Ethan leapt off the shore and onto the airboat as he looked back at her.

'We can come back for them!' He turned to Bryson and pointed down the river. 'Drive, damn it!'

Bryson gunned the engine as Lopez jumped aboard and the airboat span on the spot before accelerating out into open water in pursuit of the camera. As the deck heaved, Ethan saw a broken bottle of Jack Daniels rolling about near the stern. Lopez spotted the bottle and glared up at Bryson.

'You were supposed to be covering our backs!'

'I was. He got lucky.'

'What, lucky that you were drunk?' Ethan challenged. 'How the hell did you ever get into the SEALs?'

Bryson glared at Ethan but said nothing.

'He's out of sight,' Lopez complained. 'We won't catch him now.'

Ethan scanned the broad horizon of reed beds and water ahead. He raised his hands and used his fingers to make a box shape, focusing on one small area at a time just as he had in Miami. A few moments later he spotted a fine haze of translucent blue smoke hanging on the listless air a hundred yards ahead, the trail weaving between towering walls of reeds and sawgrass islands.

'There!' he shouted, pointing between the islands. 'He went through there.'

Bryson guided the airboat into a steep turn, white water spraying in glistening clouds from beneath the hull as they plunged into the narrow corridor. The smell of burning oil tainted the air, a tantalizing hint that Ethan's shot had fatally damaged the airboat's engine. The dense reed banks flashed past on either side of the airboat as it raced between them toward a gap that opened out onto a broader flood plain ahead.

Ethan pulled the M-16 into his shoulder and crouched down on one knee at the bow as he scanned the narrow horizon ahead for any sign of the other airboat. Lopez moved alongside him, her own rifle at the ready as the opening ahead loomed up on them.

They burst out onto the open water and Ethan looked left and right. A flash of gray metal caught his eye to his right, and he shouted a warning to Bryson as he saw the other airboat launch toward them from where it had been waiting in ambush. Bryson span the wheel and the airboat's hull shuddered as it turned hard, but he wasn't quick enough to prevent the bow of the second boat ramming into their stern.

Ethan was hurled sideways under the impact and tumbled across the deck as the airboat beside them accelerated away, trailing a thin plume of white smoke. A clatter of machine-gun fire rattled off the decks, showering Ethan in sparks as he ducked his head down low.

To his right, Lopez rolled alongside him and let her rifle fall onto his back, using his body as a rest. Ethan remained still as she took aim and opened fire on the fleeing airboat. Four rounds cracked out, and Ethan saw at least two of them send sparks flying from the airboat's propeller.

Bryson shoved the throttles fully forward and they surged in pursuit.

'He's lighter than us,' Lopez guessed. 'Only one man aboard! We can't pass him.'

Ethan was about to reply when the big blond man looked over his shoulder and tossed something up in the air. The small black object span as it climbed and then arced down toward their airboat.

'Grenade!'

Bryson yelled the warning as he swerved the airboat aside. The craft heaved and bounced across the wake of their quarry as the grenade hit the water nearby and exploded in a towering column of white water that splashed across the deck. Ethan and Lopez ducked as a hail of supersonic shrapnel sliced through the air around them, pinging off the hull and the propeller cage in a deafening metallic ricochet.

'Just get us as close to him as you can!' Ethan yelled at Bryson.

Bryson wrenched the airboat back under control and turned back toward their quarry as Ethan shouted at Lopez.

'Covering fire! Keep that bastard's head down!' Lopez responded instantly and took up a prone position on her belly in the bow of the airboat. She took aim and fired three rounds in quick succession, the wind whipping the sound of the shots away. Through the spray Ethan saw the big blond man flinch and duck his head down.

Ethan crept forward onto the port bow, staying clear of Lopez's rifle as he prepared to make the jump.

'You can't take him on your own!' Lopez shouted. 'We already tried that. Just let me take out the engine!'

'No!' Ethan shouted as a plan formed in his mind. 'I've had an idea!'

Lopez looked up at him from behind the scope of her rifle but Ethan didn't elaborate. His idea wasn't without risk, and this wasn't the time for debate. The big blond man had realized that they were almost alongside him, and in an act of desperation he did the last thing that Ethan had expected him to.

He yanked the airboat across their path, the hull banking steeply in front of them until they could see deep inside as they rushed toward it on a collision course.

43.

The airboat slid broadside amidst a wall of churning white water, its spinning propeller spraying a vortex of water vapor onto the hot air, and Ethan realized that there was no way that they could avoid smashing into it.

Bryson yelled out in alarm as he desperately tried to turn the airboat away from the impending collision. Ethan threw himself down again onto the deck as the bow of their airboat crashed into their opponent's hull in a whining crescendo of clashing metal. Ethan felt the airboat mount the bow of the boat below them, screech across it and crash down onto the water on the other side.

Ethan rolled over in time to see the big blond man kneeling in his violently rocking boat, his rifle pulled into his shoulder. A fearsome blast of automatic fire smashed into their engine, the huge propeller blades shattering to clatter against the inside of the cage as a dense pall of oily black smoke spilled from the engine block.

The blond man reached down and threw the throttles of his airboat forward, the craft surging forward past them. Two words passed unbidden through Ethan's mind.

Semper fi. The motto of the United States Marines. Always loyal.

Ethan scrambled to his feet and sprinted across the rocking deck of the airboat. He leapt into the air as the blond man's airboat thundered by, arms outstretched for the one place where the killer could not fire. The cage around his own engine.

Ethan hit the huge cage with a deep thump that reverberated through his chest as he landed. His fingers ached as they grasped the metal wires and the windblast from the blades pummeled his chest.

The airboat accelerated across the water, the vibrations from the engine shuddering through Ethan's bones as he struggled to maintain his grip on the cage. The blond man sitting in the pilot's seat could not fire through the blades at Ethan for fear of destroying his own craft, and the metal cage prevented him from reaching around it with his rifle to shoot Ethan off. The killer instead aimed his airboat at a dense bank of towering sawgrass.

Ethan braced himself as the blond man turned the vessel, sweeping along the edge of the reed banks. Thick blades slapped and sliced across the rear of the airboat, scraping painfully across Ethan's face and tearing at his shirt, but he held on grimly as the airboat soared back into open water.

Ethan reached up and hauled himself onto the top of the cage, the wind and spray stinging his eyes. As the blond man looked over his shoulder to see if he had dislodged him, Ethan hurled himself down onto the killer's broad shoulders.

The impact felt as though Ethan had hurled himself against a tree. The blond man roared as he was propelled forward to fall flat onto his face against the seats in the boat's hull. Ethan tumbled over him and rolled into the bow alongside the camera that he sought. He grabbed it with both hands and scrambled to his feet just as the killer rushed toward him with huge hands outstretched.

Ethan ducked down beneath the giant arms and barged his shoulder deep into the man's belly, spinning him aside to topple onto the deck as Ethan made a grab with his free hand for the M-16 propped alongside the driver's seat. He grabbed the butt and turned as he let the weapon slide down through his hand until his finger slipped onto the trigger. He took aim.

The blond man's fist smashed the barrel aside even as Ethan squeezed the trigger. The weapon stuttered as it fired and the barrel flew up into the air from the recoil. Another chunky fist flashed toward Ethan's face and he ducked his head down, letting the solid bone of his skull take the full impact of the blow. He heard the blond man howl in pain as his knuckles crunched across the top of Ethan's head, but the huge force of the punch sent Ethan reeling across the boat. He collided with the row of seats and sprawled onto the rolling deck. The camera was pinned beneath him and dug painfully into his ribs as the M-16 span from his grasp and clattered out of reach.

He crawled onto his hands and knees and reached out for the weapon, only to see a heavy boot swing upwards to thump squarely across his chest. Ethan gasped as his lungs convulsed and he was flipped over onto his back, his hands wrapped around the camera. The killer reached down and picked up the M-16, looming over Ethan against the blue sky and aiming the rifle down at him. The blond man's angular features contorted into a malicious grin and his eyes shone with hatred.

One thick finger curled around the trigger and squeezed.

A flash of green reeds blasted into Ethan's field of view as a crash of rending metal screeched in his ears. The M-16 flew high in the killer's grasp, the shot smacking through the hull inches from Ethan's head as the man was hurled forward through the air over Ethan's body. Ethan curled up into a fetal ball as the airboat slammed into dense coils of mangroves and launched itself clear of the water. Ethan felt himself float briefly in mid-air before the airboat slammed bow-first into a thick bank of trees. Ethan hit the deck hard and cracked the back of his skull as he flew toward the bow and was hurled out of the boat.

He saw the world spin and then the ground rush up at him in a blur. On instinct he threw his hands out to break his fall and the camera span from his grasp. He hit the foliage with a tremendous impact that blasted the air from his lungs and sent spots of light spiraling across his vision. He rolled twice across the hard and unforgiving ground and slumped to a halt against the gnarled trunk of a tree.

For several moments he lay unable to move, his lungs devoid of air, his limbs numb and his vision blurred into a haze of disconnected whorls of color. Somehow he managed to suck in a lungful of air, and his sight sparkled and returned. The sound of crackling flames entered the battered field of his consciousness, and he turned to see the buckled wreckage of the airboat crunched up against a thicket of trees, black smoke and flame spitting from its ruined engine.

Ethan struggled to focus and looked to his left just in time to see the big blond man run into the dense forests nearby with the camera tucked beneath his arm. Ethan reached out to haul himself up alongside the tree he had fallen against, but bolts of agony shot across his shoulder and he slumped back down again.

'Damn.'

Ethan lay on the bank for almost twenty minutes until he saw Bryson and Lopez paddling their crippled airboat up the creek toward him, homing in on the spiraling pillar of dirty smoke that stained the bright blue sky above.

Bryson guided the airboat in to the shore as Lopez hopped off the edge of the deck and rushed to Ethan's side.

'You didn't get the camera,' she observed.