Ethan nodded and looked at Jarvis, who was huddled down behind a bulwark alongside the pressure suit, as he held a hand to one ear and his cellphone to the other.

'We've got to hang on until he gets the cavalry here.'

Lopez nodded and then clapped Ethan's shoulder.

'I've got an idea, be ready to shoot again.'

Lopez staggered across the heaving deck as a wall of spray hissed over the boat's bows. Bryson had aimed directly for the speedboat this time, and the psychological effect of their actions was already forcing their enemy to hang back and circle beyond weapons range.

'They're coming back!' Bryson shouted, as the speedboat suddenly turned hard into them and rushed head-on once again.

'Bring them down the starboard side!' Ethan heard Lopez shout to the captain.

Ethan shifted his position slightly as he heard the speedboat's powerful engines growling and the familiar rattle of gunfire as the men aboard opened up once again. Ethan risked a glance over his shoulder, and saw Lopez hefting an oxygen cylinder onto her shoulder as she balanced against the pitch and roll of the deck.

The speedboat thundered by and hurled a wall of spray up against the Free Spirit as Lopez took two paces forward and threw the oxygen cylinder in a graceful arc across the open water. She crouched down on the deck with her hands over her head as bullets hammered the deck around her.

The silvery cylinder slammed into the back of the speedboat, crashing through the legs of one of the shooters and flipping him over onto his back. As the speedboat turned away Ethan aimed once again and fired three shots at the cylinder. The second shot hit it even as he pulled the trigger and let fly the third round, and the cylinder wall ruptured. A blast of high-pressure oxygen burst out with the force of a jet engine's exhaust and the heavy cylinder flew across the speedboat's deck and smashed into the back of the pilot's legs, shattering them with a metallic clang that Ethan could hear even above the Free Spirit's laboring engines. The cylinder spiraled crazily across the speedboat's deck as the pilot collapsed in agony, trailing a cloud of vapor as it crashed into the engines before shooting into the air and spiraling into the ocean thirty yards away.

Ethan saw a thick cloud of black smoke billow from both of the speedboat's engines as a limp body toppled over the taff-rail into the ocean in a tangle of flailing limbs. The speedboat began turning lazily in circles, its idling engines spitting flames that began to burn their way along the hull.

'That'll do,' Ethan smiled grimly as he stood up.

'We're not out of trouble yet,' Bryson called out.

Ethan saw the big man pointing out toward the horizon, where two more speedboats raced toward them on an intercept course.

27.

FLORIDA STRAITS, 14 MILES WEST OF SOUTH BIMINI.

'How much more ammunition do we have?' Ethan shouted.

Bryson yelled over his shoulder as he turned the Free Spirit toward the distant Florida coast.

'None! I only carry the rifle to finish off big catches like sharks and marlin!'

Ethan checked the weapon and saw only a single round remaining.

The two speedboats turned in unison alongside the Free Spirit, and Ethan saw four men aboard each vessel, all aiming their weapons directly at him. He looked across at Jarvis, who had lowered his cellphone from his ear and was watching their attackers with an expression of disbelief.

'Who the hell are these people?' he called out.

'I don't suppose the Coastguard's on its way?' Lopez asked.

'Not exactly,' Jarvis shouted back.

Ethan stared at the speedboats and felt a lance of fear pierce his guts as he watched one of the gunmen lift what looked like a grenade in one hand, pulling the pin with the other and swinging his arm back to lob the weapon toward the Free Spirit.

'Hard to starboard!' Ethan yelled to Bryson.

The captain span the wheel to the right, and as he did so a thunderous blast of noise blazed overhead. For a terrifying instant Ethan flinched against the expected shrapnel as the unseen grenade exploded around them, but then he saw a flash of metal above them in the sky and a sound like that of a playing card caught in the spinning spokes of a bicycle.

An enormous fountain of white water erupted around the speedboats, a curtain of churned foam that zipped across the ocean at tremendous speed. Ethan saw both of the speedboats shudder as clouds of debris blasted into the air to spill onto the surface of the ocean, the gunmen and pilots torn apart like rag dolls. The grenade fell from the gunman's hand to land alongside him in the speedboat.

'Get down!'

Ethan, Lopez and Jarvis dropped down as the grenade detonated and the speedboat lurched as its engines failed and its rudder was torn off in the blast. The stricken vessel collided instantly with the other speedboat, smashing through the hull and splitting the second vessel in half. The two boats flipped up into the air and crashed back down onto the surface of the ocean amid a churning cloud of foam.

Ethan craned his head up and spotted a pair of F-15E Eagles turning sharply across the blue sky, bright white vortices trailing from their wingtips. He looked across at Jarvis, who shrugged as he brushed himself down.

'Why call the Coastguard when you've got the Air Force on the line?'

Ethan got to his feet, steadying himself on the deck as Bryson eased back on the throttles. Across the water, Ethan could see the two speedboats and the bodies of their attackers sinking rapidly beneath the waves, leaving only debris and an oily slick of spilled fuel floating on the surface.

'Who were they?' Lopez asked him, shaking chips of fiberglass from her hair.

'I don't know, but I'd like to find out. How deep is the water here?' he asked Bryson.

'Hundreds of fathoms now we're off the sandbar,' came the reply. 'You'll need the Navy to recover the boats. The bodies might float up after a few hours, provided they're not eaten beforehand.'

Ethan shook his head. Even if the bodies did survive scavengers, they'd likely be carried for miles by the currents and be lost far out to sea. He turned away and looked at the damaged deck of the Free Spirit. Bullets had hammered almost every spare inch of her. Ethan crouched down and ran his hand across the scarred surfaces until he found what he was looking for.

'You got any sealable bags aboard?' he asked the captain.

Bryson turned to one of the deck lockers and lifted out a small polythene bag used to hold live bait in water. He handed the bag over, and Ethan grabbed his knife from its sheath on his diving suit. He probed into one of the jagged tears in the deck and prized from its depths the crumpled remains of a bullet. Jarvis watched as Ethan dropped the bullet into the bag.

'What are you thinking?' the old man asked.

Ethan stood up and looked at the rolling ocean around them. There wasn't a single other boat to be seen, nothing but endless sea and blue sky flecked with puffy white clouds. Lopez guessed his thoughts before he voiced them.

'Something to do with Purcell?' she suggested. 'He wanted us to be here after all.'

'What, to get us killed?' Jarvis uttered.

Ethan looked at the bullet in the bag.

'I don't know, but one thing's for sure: we didn't advertise our presence and Captain Ahab's boat here is just one among thousands moored in Miami.'

Bryson ignored Ethan's flippancy. 'Did you find the aircraft?'

'Yeah,' Lopez nodded, 'along with all of the occupants. And that's what doesn't figure. There were divers down there. They tried to ambush whilst we had our noses stuck into that airplane.'

Bryson squinted at the flotsam now drifting on the ocean nearby.

'We didn't see any divers leave those speedboats.'

'That's because they were already there,' Ethan said. 'It was an ambush.'

'But they couldn't have known we would be here,' Jarvis protested. 'Unless somebody on Kyle Sears' team is acting as an informer.'

'The police?' Lopez replied. 'I thought Kyle's team were kept out of the loop?'

'They were,' Jarvis agreed, 'but we can't guarantee that somebody with inside knowledge wouldn't be keeping an eye on us.'

'It's possible,' Ethan said. 'There was a buoy tethered to the tail of the aircraft wreckage, very small, but it could have held a camera.'

'We need to find it,' Lopez said.

'You won't,' Bryson cautioned her. 'The sea's so choppy we could be right on top of it and not spot it. It would take hours.'

'Hours we don't have,' Jarvis agreed.

'Somebody must have been here before us.' Ethan looked down at the bullet in the bag in his hand. 'Purcell's family were killed by bullets that were dipped in something called Rubidium-82,' he said. 'I'm hoping that these bullets have traces of the same compound.'

Jarvis looked at the slug.

'You think that Purcell's being hunted by the same people who were shooting at us?'

'Maybe,' Ethan said. 'Chances are the two are connected, and that could mean that Purcell is waiting for us to make that connection before he comes out of hiding. Once any doubt can be thrown on his role in the killing of his wife and child, he'll be able to start fighting his own corner.'

Lopez shook her head.

'But he could have done that anyway, just gone straight to the police with all of this information instead of leading us on a chase and nearly getting us killed. What good will it do him if we, the only people who know about his possible innocence, get iced?'

Ethan shrugged.

'I don't know, but right now it's all we've got for his motive. Somebody is hunting Purcell and us at the same time.' A thought occurred to him and he turned to Jarvis. 'What if Purcell saw into the future using somebody else's equipment? We're assuming he did it himself somehow, but he's been working freelance since leaving NASA, right? Purcell might have only a limited amount of time to clear his name. He said he was going to be murdered, right? We got any idea who he was actually working for when all this started?'

Jarvis nodded.

'Some corporation called IRIS,' he said. 'He was privately contracted, so we don't have any real details of what he was doing for them.'

'I've heard of IRIS,' Lopez said. 'Big charity headed by that Joaquin Abell who's always on television screaming for donations.'

Bryson chimed in from where he was leaning against the wheelhouse.

'IRIS is whiter than white, totally non-profit.'

Jarvis's cellphone trilled, the musical tone sounding strangely feeble amidst the vastness of the open ocean. Jarvis flipped it open and answered, listening intently for a few moments before he raised an eyebrow.

'You're kidding?' The voice on the other end of the line warbled for a few moments more. 'Okay, we're on our way.' Jarvis snapped the phone shut and looked at Bryson. 'Head for shore, pronto. Something's come up.'

Bryson remained leaning against the wheelhouse.

'Once we're ashore that's it; we're done,' he replied. 'This trip's already cost me a lot more than I bargained for.'

Lopez turned to the captain.

'We hired you for this,' she pointed out, 'and for a lot of money.'

'Yeah, sure you did,' Bryson agreed as he turned toward the wheelhouse. 'And that money's what I'm going to need to rebuild my goddamned boat!'

Ethan saw Lopez's crestfallen expression as Bryson stormed off up into the wheelhouse and threw the throttles forward angrily.

'We're done with him anyway,' Ethan said to her before turning to Jarvis. 'Who called?'

'My office was left with the task of monitoring any evidence of Charles Purcell's whereabouts. His name's just turned up as a witness in a court case being held today in Miami.'

'Let me guess,' Lopez said. 'IRIS?'

'One and the same,' Jarvis confirmed. 'Looks like Purcell turned whistleblower on the company, sent documents to a prosecutor in the city. Could turn the case in the prosecution's favor and expose corporate fraud by IRIS executives.'

Ethan looked again at the bullet in his hand.

'What's the chances that we can get this bullet analyzed today?'

'I'll see what I can do,' Jarvis said. 'In the meantime we need to get to that courthouse as fast as we can. There's people there we need to speak to.'

'Who?' Lopez asked.

'The prosecutor, a Macy Lieberman, and the defense lawyer. Turns out she's none other than the wife of IRIS's Chief Executive Officer, Joaquin Abell.'

Ethan looked about them at the empty ocean and thought for a moment.

'We get codes from Purcell hinting at future events,' he said. 'He's seeing things that haven't happened yet. Then people turn up here and try to kill us before we can figure out what happened to this downed aircraft. Even if they did have a camera out here on the ocean, they couldn't have gotten out here so fast without knowing in advance that we would be here.'

Jarvis balanced on the boat's rolling deck.

'Nobody on the police force could have placed a camera all the way out here without somebody knowing about it,' he added. 'That rules out a mole in Kyle Sears' department.'

Ethan was about to respond when he saw in the water a small, round object bobbing on the waves. He leaned over and saw a buoy half sunk in the water, its shape distorted by the impact of a bullet. The round, black eye of a camera lens looked out at him as the buoy slowly sank into the churning water.

'Which means one of two things,' Lopez surmised as Bryson turned the boat around to head back toward Miami. 'Either Charles Purcell wants us dead, or somebody else is able to see into the future.'

28.