Aftershock (28 page)

The Hummingbird hovered just out of range of the ELF beam. The missile relaying the destructive pulse from the Chinese base was circling around the crash site 85 kilometres west of their position. From images beamed to them by BigEye 17, they had a clear view of the area on the wall screen in the main control room of the giant aircraft.

Dimitri in the Silverback was directly above the crash site, descending very fast. ‘Target locked,' he said through the comms, his voice booming out of the speakers. ‘I'm going for a 2 square kilometre sweep with the ultrasound. Prepped and ready.'

‘Copy that,' Josh replied. ‘Make it quick, Dimitri.'

‘Don't you worry, my friend. I plan to.'

They watched the sleek jet twist over the wreckage, 21,000 metres above the frigid sand of the Gobi. The sun sparkled off its green fuselage as it plummeted. Then, pulling up, Dimitri levelled off at 10,000 metres, changed course to a heading of 67.44 degrees and set the controls ready for the dive.

It would take all the man's skill to pull off this delicate operation. He would have to swoop down at Mach 2, twice the speed of a bullet, level off at an altitude no greater than 300 metres, purge the area with ultrasound, then pull up and climb to a safe altitude while all the time avoiding the Chinese disruptor beam.

‘Okay, Hummingbird. I've levelled off.'

‘You're well clear of the beam.'

‘Good. All systems check green.'

‘Copy that here.'

‘Anything from Tintara?'

‘Tom's doing his best, Dimitri. Remember ... top speed Mach 2. Go a fraction faster and you'll risk losing trim and...'

‘I know, Josh.'

‘Yeah, sorry, man.'

‘All right.' Dimitri's voice spilled from the speakers. ‘Let's do this.'

Bundles of information pulsed along the tube. Tommy Boy stared at them zipping past his feet. They glowed every colour imaginable and some he had never conceived of before. Then he leapt forward, grabbed hold and rode the information stream.

He found he could steer the bundles simply by thinking where he wanted to go. And he knew where he was aiming for – the central processor. The fact that information bundles were still moving meant the system was still operating. His mission was not yet accomplished. He had to get to the core of the Chinese computer and take it out.

A fraction of a microsecond and he was there. The outline of the processor grew on the horizon. The information bundle hurtled towards it. Tommy Boy jumped off his ride with precision timing and flew into the heart of the machine, tumbling onto a hard metal floor and rolling over.

‘Get up,' said a voice.

Tommy Boy lifted his head. An old man was standing in front of him. He was leaning on a gnarled staff made from some exotic pale wood. Behind him stood the central processor for the Chinese computer system. It hummed quietly. Bundles of information were streaming in and out of it. Tom's avatar pulled himself to his feet.

‘I am the guardian. It was unwise of you to come here,' the old man said.

Tommy Boy stared at him, silent.

‘Your virus has weakened us. I cannot destroy you. But I can stop you from controlling the processor.'

Tommy Boy ignored the old man and dashed towards the processor. He slammed into some sort of invisible barrier and fell back in a heap on the metal floor.

The old man cackled, shaking his head slowly. ‘Ah, the folly of youth.'

Tommy Boy pulled himself up. Time was running out. He took another run at the processor and was thrown back again. Then he turned on the old man and swung his arm round to smash his fist into the guardian's face. Instead, he found himself sprawling on the floor again.

In Cyber Control, Tom shook in his chair. His heart was racing, eyelids twitching.

Tommy Boy went for the old man again. This time, he caught hold of his tunic. The guardian swung around as nimble as a young boy. Tommy Boy clung on and tightened his grip. New strength came from desperation. He managed to pull the old man towards him and they fell to the floor in a confusion of limbs. Tommy Boy clawed and grasped, never letting up. The old man folded under him, his wooden staff flying away. Tommy Boy punched him hard in the face. He went to hit him again and the old man laughed. Tom's avatar held back, fist poised in midair.

‘You'll never break into the processor,' the old man gasped.

‘That's what you think.'

‘It is what I
know
. Consider the prime factors of that number ... there.' And he pointed to the processor. The machine was daubed with a number dozens of digits long. The old man laughed again and wriggled out from under Tommy Boy. Grabbing for his staff, he stood over him, beaming.

Tommy Boy lowered his fist, and in Cyber Control, a shudder passed through Tom's body. Now he understood. The processor was protected by pure mathematics. Finding the prime factors of such a large number as this was almost impossible.

Tommy Boy looked at the metal floor, let out a sigh and took a deep breath.

‘You realise, yes?' the old man said, his voice even, totally in control. ‘To break into the processor you must find two prime numbers that multiply together to give you this number. Perhaps you should go now. Return to your friends. Let us get on with our duties.'

Tommy Boy continued to look at the metal. And as he did so, the fear fell away from him. The old man was right. Finding the prime factors of this huge number was almost impossible. It would take a computer thousands of years to calculate. But the old man obviously had no notion of Sybil, the quantum computer. When Tom raised his head, it was he who was smiling.

The old man fixed him with a serene look.

Tommy Boy was about to speak to Cyber Control when the guardian lifted a hand. He looked straight into the avatar's eyes.

‘Oh ... and no cheating,' he said, and Tom felt the comm link with Sybil snap.

‘Shit! What's happened?' Noel Brannigan exclaimed and span around, staring at Tom slumped in his chair. The CyberLink was still attached, his eyelids flickering.

‘We've lost the comm connection between Tom and Sybil,' one of the techs responded. ‘Every other system is up and Tom's getting sensory information in the cyber world. But that's it.'

Noel Brannigan closed his eyes tight and screwed up his face.

‘What do we do?' the tech asked.

Noel opened his eyes and stared around the room. ‘I have absolutely no idea.'

On the Hummingbird screen, Josh and the others could see the Silverback making its final turn 6000 metres above the desert. As they watched, it dropped like a stone out of the bright blue sky, moving so fast the cameras on BigEye could barely keep up.

‘Ultrasound coils set,' Dimitri said through the speakers. ‘Final systems check A-okay. Four seconds to range.'

They all heard the squalling sound from inside the Silverback. It was so loud it almost blew the speakers in the Hummingbird's control room. Then a computer voice aboard
Mick
cut through the sound. ‘Warning, warning. Unidentified electromagnetic disturbance. Abort, abort.'

Omar span in his chair to face Josh. ‘His starboard engine is hit.'

‘How bad?'

‘Fifty per cent efficiency and dropping. Forty per cent.'

‘Dimitri, pull up,' Josh yelled into his headset.

No reply.

‘His comms are down,' Omar said.

‘Aggh,' Josh screamed and hit the control panel with the palm of his hand.

‘Port engine hit,' Omar reported. ‘Seventy per cent efficiency.'

A crackle came over the comms and Dimitri's voice could be heard, fragmented, distorted. ‘Hummingbird ... get the damn thing ... I'm ... try...'

‘Warning, warning,' came the metallic rasp of the computer aboard the Silverback. ‘Electro ... serious ... compromi ... abor...'

On the screen, they could see the Silverback levelling off no more than 100 metres above the desert. It screamed over the wreckage, and somehow Dimitri was keeping control of the plane. But they could all see what a struggle it was – the wings kept dipping, and every few seconds the Silverback juddered. The plane started to climb.

‘Starboard engine down to 10 per cent.'

Then suddenly the interference over the comms vanished and the squalling sound disappeared.

‘Dimitri,' Josh shouted.

‘Hummingbird.'

‘Get out, Dimitri.'

‘Couldn't get the ultrasound online,' he said.

Looking at the big screen, Josh saw the plane bank around and start to make a second run.

‘Dimitri. Get out. That's an order!'

Dimitri's reply came as fractured words. Then the ear-splitting squall crashed through the speakers louder than before.

Tommy Boy stared in disbelief at the old man. He could feel the panic rising inside him but knew that to react to it would be fatal for the mission. Instead, he tried with all his strength to calm his breathing, to steady the shaking in his hands, to think clearly, analyse, analyse. That's what he did best.

The old man's smile was infuriating. Tommy Boy felt an overwhelming desire to smash the wizened face with his fist, pummel it to nothing. He could not win this battle, but he could smash up the old bastard good. It would be a hollow gesture and achieve nothing. He knew that. He also knew how hard it would be to calculate the prime factors of this number himself. It would take a human being without the benefit of a computer longer than the lifespan of the universe. Whatever Tommy Boy did, the old man would win.

The guardian sighed and narrowed his eyes. Then he broke into a laugh, a triumphant cynical laugh. And it was at that precise moment that Tommy Boy had a brilliant idea.

The old man gave him an odd look as the avatar lowered himself to the floor cross-legged, arms behind him, palms flat to the metal floor.

Hands out of sight, Tommy Boy began to tap.

‘We've gotta unhook him,' exclaimed Madeleine Alexander standing beside Tom's chair.

‘No, that would be disastrous,' Noel shouted leaping from his seat. ‘Both for Tom and Sybil.'

‘Well, what then?'

Noel ran a hand through his hair and stared around the room, desperate for some clue, some answer.

‘What's he doing?' It was one of the techs on the other side of Tom's wheelchair.

Noel and Madeleine both looked at the tech, and then round at Tom. ‘What do you mean...?'

‘There. He's tapping his fingers.'

Noel took a step forward and crouched down beside Tom slumped in his wheelchair. The young man's head was tilted to one side, the CyberLink headset clung to his scalp. His eyes were closed, but they could see his eyeballs moving, his lids flicking rapidly as though he were in REM sleep. Glancing down to where Tom's hand was resting on the leather armrest, they could all see his fingers moving, drumming out a rhythm.

‘What...?'

‘It's Morse Code.' It was Madeleine's voice. She was standing behind Noel, staring at Tom's fingers.

‘Morse...?'

‘He's tapping out a message. Get me a pad and pen,' she snapped turning towards the nearest panel. ‘Quick!' A tech ran forward and Madeleine stared scribbling.

‘What the hell's he saying?'

‘Sssh.'

They fell silent.

‘It's part way through. Just numbers. Start again, Tom,' Madeleine urged, knowing he could not hear her but needing to say it.

‘Words,' she said as she scribbled.

‘What words?'

‘He's saying ... Prime factors. He wants prime factors. Must be a security barrier. Hang on, the numbers again.' She scribbled more digits onto the notepaper in her hand, flicked the page, writing frantically, knowing she could not afford a single mistake. ‘Yes ... yes, I'm back to where I was,' she said triumphantly. ‘Got it.'

She dashed over to the control panel, tapping at it and talking twenty to the dozen. ‘It's a bloody huge number. More than 40 digits.'

‘But Sybil can do it.' One of the techs interrupted.

‘That's why their defence system cut the link,' Noel replied. ‘They can't stop Tom being there, but they can stop him getting into the central processor which must be guarded with this “insoluble” problem. Well done Tom!'

‘There,' Madeleine said, and stepped back from the console. ‘Now it's up to Sybil.'

‘How long?' Noel asked.

‘That's harder to answer than the problem,' Madeleine retorted.

On the big screen, the jet was just a blur as it streaked down vertically through the crisp desert air.

‘Warning ... warning.'

‘Same thing,' Josh hissed. ‘Same fucking thing. God!'

Omar was in the seat beside him, staring at the screen.

Again Dimitri's distorted voice crackled over the speakers. ‘Ultrasound primed,' he said. ‘Altitude ... ousand metres ... level...'

‘Warning. Warning. Abort ... ystems ... criti ... Abo...'

The plane levelled off.

‘Both engines down to 11 per cent,' Omar said. ‘Damn it!'

‘What?'

‘ELF signal power is increasing.'

Josh stared at him and bit his lower lip.

‘Humming ... I'm losing...'

‘Warn ... arning ... Ab...'

‘Unidentified aircraft approaching crash site.' It was a clear voice – the Hummingbird's onboard computer.

Josh swung around to face the control panel, and there in the holoscreen he could see the shape of a transport aircraft.

‘What's its ETA?'

‘Thirty-five seconds.'

‘Come on, Tom!' Josh said under his breath. ‘Come on!'