It was the sound of an engine.

'I'm no expert,' said Amber, 'but that sounds like a quad bike.'

'The gamekeepers,' said Hex. 'We'd better get out of here.'

The six-wheel ATV crested the hill. A figure stood upright behind the driver. His posture was unmistakable head to one side, looking along a barrel. A shot rang out.

Li felt the ground explode by her heel. She did the only thing she could run.

Hex and Amber took off in zigzagging lines behind her. If they gave the shooter several targets, it might slow him up. Amber rolled into a gulley. She heard shouts and a rifle bolt being pulled back. She started to pull herself along in the water in case they'd seen her go in. Hex followed her down, then Li quickly tumbled in after him. They were all like soldiers in a trench.

The stream bed made a narrow channel like a miniature canyon. Hex began to pull himself along on his elbows. The others followed, crawling as fast as possible. They might as well move while they could.

They heard the ATV's engine rev. Good, that would cover any sound they made. Hex got up on hands and knees and stepped up the pace. Amber and Li were right behind him.

Suddenly he stopped as he saw the end of the stream bed. 'It's a dead end,' he hissed. 'They know we're in here. We need to get out.'

Li cautiously peered out and nearly had heart failure. Right by her nose was a pair of st.u.r.dy walking boots and argyle socks. The gamekeepers weren't both on the ATV any more. The one with the gun was right here.

Too late to retreat. Li took her courage in her hands. She exploded out of the gulley and knocked the gamekeeper over. His gun went off and she twisted it out of his hands and threw it away like a javelin. He grabbed at her leg but she gave him a vicious kick on the chin.

The others darted out of the trench. The gamekeeper on the ATV gave chase. Amber saw a steep slope and headed down it. Hex hared after her and Li followed close behind.

Another shot whistled past Hex's ear. He caught a glimpse of a man at the top of the slope, ready to fire. The gamekeeper must have retrieved his gun. The ATV droned behind him. Maybe the man wouldn't fire with the ATV in the way. But now the vehicle was their main problem, not the gun.

Amber was in front. Hex moved away from Li. If they stayed together they presented an easy target. With several of them moving in different directions, it was more confusing.

The slope was getting steeper. Li needed all her balance not to fall over. Suddenly she heard the whine of the engine and the bounce of the axles right behind her. The ATV had given up on Hex and Amber and was now after her. She felt its wheels pushing the long gra.s.s onto her calves and leaped to the side. She was too vulnerable on her own.

The slope fell away even more steeply. Li ran back towards Hex and Amber, using her hand to keep herself upright. The ATV had slowed, but so had they. And what was Amber doing?

Amber veered back up the hill, climbing on all fours. The ATV swerved and the wheels on one side left the ground. As Amber watched it, she could see that the driver's pockmarked face was pure panic. Abandon ship, she thought. Just step off. If you stay on, it will fall over and crush you.

But the ATV bounced back onto six wheels. d.a.m.n, thought Amber. Then the driver stopped and took out a weapon. A sawn-off shotgun.

Hex ran in from the side and elbowed him roughly off the vehicle; the shotgun spun through the air. While Li leaped onto the flat bed at the back, Hex pressed the throttle switch and turned the handlebars so they were pointing straight downhill. Li hooked her arms under Amber's shoulders and hauled her on.

'Go go go, Hex!' shrieked Amber.

A shot rang over their heads but Hex opened the throttle to full. If they went in a straight line they could go at the vehicle's top speed. He lay back on the seat, his feet on the foot rests, trying to keep his balance. Behind him Li's and Amber's heads b.u.mped against his. But they were getting away.

However, the slope wasn't smooth and Hex wrestled to keep the handlebars pointing straight downhill. The wheels clattered loudly on the cha.s.sis; if they started to go at the slightest angle, the machine would tip over for sure. He didn't know how Li and Amber were staying on but he prayed they wouldn't let go.

The girls were spread-eagled on the flat bed, hands and feet hooked onto whatever they could get hold of. Amber had an excellent view of the fat tyres, spinning crazily. Li was clinging to her. She was terrified she would slip and knock Hex off. The ground went past in a bouncing, rib-battering blur.

A shot rang out. They weren't out of danger yet. Hex kept his thumb on the throttle. The speedometer was climbing steadily. Now it said 66 kph. Some small compartment of Hex's brain that loved numbers gave a little smile: that was about 10 kph above the vehicle's top speed. With this slope they must be breaking records.

Suddenly Hex realized he couldn't see the ground ahead. There just seemed to be a kind of shelf, and then some more gra.s.s a little further away. They were heading for a sheer drop.

Hex squeezed the brake. It made little difference. After all, they were doing record-breaking speed. The edge came up fast. There was nothing he could do. 'Hold tight!' he yelled.

He stood up in the foot rests like a jockey and hoped for the best.

Li and Amber found they were looking down on water. For a moment they seemed to hang there, like a gliding bird.

The impact was like hitting a wall. A great wave of freezing water engulfed them. Hex felt himself going over the handlebars. He clung on and his arms nearly came out of their sockets. There were m.u.f.fled cries from behind.

Underneath him, the bike slowed and bounced. The tidal wave settled and Hex found himself standing on his foot rests, up to his waist in the icy water of a river, with the engine still running.

He looked behind him. Amber was pulling Li back onto the flat bed. Li's cheek was bleeding.

'Nice one, Hex,' said Li, breathing hard.

Amber was panting. 'What now?'

Hex looked up at the mountain. They had left wavy tracks like a double pinstripe down the hill, but there was no sign of the gamekeepers. He slowed to a stop and cut the engine. 'We've lost them. Maybe we should leave the bike here and continue on foot.'

He tried to get off, but his legs had turned to jelly after the effort of holding his position on the bike. Amber started to let go of the flat bed, but her fingers wouldn't obey. She had to uncurl them slowly. Li let out a long, slow breath and tumbled off the ATV.

They splashed through the water onto the river bank.

As soon as they climbed out onto dry land Hex was checking the GPS.

'Where are we?' asked Amber.

Hex grinned. 'Well, we've travelled approximately four hundred metres from where the factory is. Vertically.'

Li circled her arms. 'Yes, I realize that.' She grimaced and the cut on her cheek squeezed out a tear of blood.

Hex looked up. The ground formed a natural ridge. 'If we stay in close to the ridge we should be out of sight from above.'

'Better hurry,' said Amber. 'They could easily follow us.'

She forced herself into a jog and the others followed. They were tired and aching, but it was vital that they put as much distance as possible between themselves and the gamekeepers.

Paulo opened the front door of the hostel. 'Well, poor Martin Fletcher's had a day to remember,' he said. He and Alex had been with the hiker to the police station to report the arson attack on the bothy. The police took statements and said they would send officers to inspect the site, but it was clear they were treating it as a simple case of vandalism.

From the kitchen came sounds of activity. Alex shrugged off his Gore-Tex jacket and hung it on the peg. 'Let's go and see if the others found anything.'

They were shocked at what they saw: Amber was dabbing antiseptic on a cut below Li's eye; Hex was stretching his legs and arms as though his joints had seized up; and Amber's fingers were wrapped in plasters.

'What on earth have you been up to?' said Hex. 'You smell like a bonfire.'

'You look like you've been in a bullfight,' said Paulo. 'All three of you.' He pulled out a chair and sat down. 'Do you want to go first or shall we?'

They briefly summarized the events of the morning. Alex felt drained: it was good to sit down. Suddenly he had a thought. He sat bolt upright.

'What's the matter?' said Li.

'I don't think we should be here,' he said. 'Look at us. Yesterday the gamekeepers were minding their own business, keeping their heads down. Now, they're defending their patch. They've shot at us and tried to burn us to death.'

Outside, tyres crunched on the gravel.

19.

REVENGE.

The five friends ran out to the hall and grabbed rucksacks and boots. Hex rushed back and s.n.a.t.c.hed up the map.

Outside, the car braked and threw a spray of pebbles at the front door.

'Out through the back,' said Amber, and led the way into the office.

Paulo raised the sash window and hopped out; the others followed. They heard the front door splinter as it was kicked open.

'Down,' hissed Alex. As they crouched down below the windowsill, footsteps echoed in the flagstoned hall.

A voice said, 'Try the kitchen.' The footsteps disappeared down the corridor.

Hex glanced up. In the window of the office he saw the reflection of figures moving through the hall. There were three of them. The one who had spoken was tall and wore a rough jumper and a blue-green kilt; one shoulder was hidden by the door frame. Then he moved and Hex saw something else. A stubby weapon.

Hex mimed holding a gun. Alex nodded. Sweat was running down his armpits and back.

Alex looked up at the hill that rose steeply behind the hostel. They couldn't get away up there. It would be too slow and they would be easy targets.

They heard voices again: the man was coming back. Alex pointed along the outside wall down towards the kitchen. Paulo crawled quickly down to the end of the building and stopped under the kitchen window. As Alex, in the rear, moved away from the office he heard the men coming in. They had got away just in time. Thank goodness the gravel didn't extend round the back of the building; here the ground was bare earth, easy to walk on silently.

They looked round the corner of the building. A battered red Ford Escort stood in the drive. It had a crumpled bonnet as though it had been used as a battering ram.

Hex spoke quietly. 'The Range Rover. It's in the garage so we'll have cover while we get in.'

Alex nodded, but Paulo shook his head. 'The keys are in the house. I'll have to hotwire it. It's got an immobilizer so it'll take ages.'

'How long?' said Hex.

'About fifteen minutes. d.a.m.n.'

'Are you sure?' asked Hex. 'The immobilizer wasn't working last week.'

Paulo winced. 'I know it's working now because I fixed it the other day.' He looked at the red Escort. 'I could hotwire that in thirty seconds flat.'

Alex shook his head. 'Too risky. They might see you.'

'They won't need to see you, they'll hear you,' said Li. She pointed to the gravel.

Paulo sighed. 'We'll have to hotwire the quads. But we need all three and by the time they'd heard the first one they'd be coming down.'

Amber said, 'You tell us what to do and we'll start them all together.'

'That's what we'll have to do,' said Alex. 'Hex, what weapons did you see?'

'Sawn-off shotguns.'

'Right,' said Alex. 'Not very accurate at a distance. If they shoot from an upstairs window they probably won't get us. But we'll try not to make any noise. Ready?'

Four heads nodded back at him.

'Alex, are you OK at the back?'

Alex nodded and watched as Paulo led the group along the edge of the gravel, running silently on the hard-baked earth. The garage was a big building alongside the hostel, b.u.t.ting up close to the steep slope behind.

Alex followed at the back. It was only a short distance but it seemed like the longest run of his life. He felt so exposed. Each moment he expected to hear the crack of gunfire. Sawn-off shotguns. Weapons of the underworld. He kept telling himself, They aren't accurate at that range, but he could almost feel the shot spraying into his flesh.

In less than twenty seconds he felt the solid wall of the garage building against his back. At last he could breathe easily.

Paulo looked round the front of the building. The garage door was open. He could see the three quad bikes and the dark green Range Rover. The others were behind him, waiting for his signal. He nodded and they darted round the corner and into the garage.

Paulo wasted no time. He unfastened the tool kit he carried on his belt, went up to the first quad and jammed a screwdriver into the housing that covered the ignition system. Hex saw what he was doing, grabbed a large screwdriver from a rack on the wall and did the same with the next bike. The red cover clattered to the floor as Hex did the same to the third one. Meanwhile Li, Amber and Alex grabbed what they could: Amber and Li took loops of rope and hung them over their bodies diagonally; Alex reached into the Range Rover and pulled out a couple of rucksacks. He threw one to Hex and put one on himself. They were emergency supplies in case they got stranded on the moors.

Amber could sec someone else was needed on the third quad and climbed into the driver's seat. Paulo pa.s.sed a couple of nails to Hex, and Hex pa.s.sed one to Amber. Li got on behind Amber while Alex got on the back of the middle bike, behind Hex.

Paulo straddled the first bike. 'See the two little things that look like metal flowers? When I tell you, put the nail across them so that the little pointy things in the middle are connected. That will crank the engine. Then get out as fast as possible.'

Two faces watched him, serious.

'Three, two, one now!'

In perfect unison, the three quad bikes spluttered into life. Paulo immediately reversed his out; Hex nearly cannoned into him; Amber took hers wider and roared off onto the drive, her wheels spraying gravel up like water.

They were right not to hang around. Two shots rang out from one of the upper windows. All five friends ducked, the drivers lying almost flat on the handlebars as they roared away.

Paulo looked for a spot to leave the road. The quads weren't road legal, and anyway the gamekeepers would soon be after them in their car. On the road, the car was much faster.

The road turned a corner. Paulo stood in the foot rests and swerved his bike round hard, onto the gra.s.s and up. Behind him, he heard the noise of the bikes change as the others did the same. But a manoeuvre like that would have left marks on the road. They had to vanish without a trace.

Paulo gunned the throttle and the bike climbed up and over the crest of a hill and then down again. They were off the skyline now. They could take a breather. He braked.

Amber pulled up alongside. 'I know somewhere we can hide,' she said. 'Follow me.'

A gentle pattering of rain started as Amber led the way into the ruined barn she had found when they were looking for Tiff.

It was just about big enough for three quad bikes. Half of the roof was still there and they managed to manoeuvre the bikes under cover. And it got them out of sight.