Carmen just stood there, screaming. Apart from her hair, which was being whipped into a frenzy by the rising wind, she was completely still.

Will reached her first and shoved her back at me. Boosted by the wind, she stumbled in my direction. I grabbed her and pulled her close. She wilted against me, clinging to my shirt with her hand. Her screaming faded into small shrieks that came on each outward breath. Her heart hammered against my chest.

Reece started laughing. “Boys, you’ve got something that belongs to me. Hand it over.” He sounded almost friendly – a good bloke to meet on a night out.

“He’s insane,” Grady muttered.

Lizzie gripped my arm. “Oh no!” She pointed back the way we had come. Curtis was climbing over the cliff edge, triumph lighting his face. He fought the wind and rose to his knees, reaching back to pull the skinny boy after him.

I looked at Will. An air of eerie calm had dropped over him. But even with Will fighting like a maniac, we were trapped: us versus ten of them.

“I’ll take the five on the left, you take the five on the right,” Lizzie said into my ear, her voice shaking.

“No, no, no…” I was on a mental loop. All I could do was plant my feet against the wind and look from Curtis to Reece and back again.

Lizzie took her knife from her belt with a trembling hand. I had my axe. Will’s pick was dangling from his left hand, as if he barely knew it was there. Grady had his fists raised and he was trembling almost as hard as Carmen.

I pushed Carmen into Lizzie’s arms.

“All right, then,” she whispered. “I’ll deal with the ones you leave!”

This fight was going to be over in seconds. Then Curtis would force us to tell them what was in the previous geocache and he’d take someone’s eye.

And after that … my eyes flickered to the final geocache box: the hollow beacon. I still had no idea how it opened – perhaps automatically, once the checkpoint box behind the plaque was solved, but it was huge. For the first time, I really began to consider what was in it.

It was big enough for a body … wasn’t it?

I grew aware that Lizzie was hissing at Carmen. “You wanted to stop them from winning – so stop them. Stop behaving like a princess in a tower and stand up for yourself.”

“Lizzie!” I was shocked. But Carmen started to straighten.

“You’re not alone, Car,” I murmured. “We won’t let them hurt you.”

“Be quiet, Ben,” Lizzie snapped. “Come on, Car, where’s the bitch I know? Where’s the freaking warrior? Will, give back her knife.”

Will grinned and shoved the knife into Carmen’s hand, and as the wind intensified to a wail, Carmen raised her head.

“It’s still five against ten.” My voice was shaking.

“No,” Lizzie hissed. “Right now it’s only Curtis and the little guy up the cliff. The rest went back down, remember? That makes seven. Five against seven. We can do it.” Her voice was high-pitched.

“That’s enough of that.” Reece started to stride forwards, flanked by his team. “I want my Spare Parts back.” He raised his hand, revealing a narrow red line on the meat of his palm. “She owes me. This has been stinging.”

I gasped. He’d taken her beautiful hand. He’d destroyed her life – Carmen, the one person who had always been full of life. And he was complaining because she’d made his hand sting.

Rage burned the fear out of my bones and a howl ripped from my throat… I bounded forwards, my mind gone.

Lizzie screamed my name and I heard Grady yelling something at her. Something about leverage. But I didn’t care. I leaped at Reece, axe raised.

Something thwacked into the side of my head, knocking me sideways. I flew into a hard body, but didn’t stop to think. I punched with one hand and rammed the handle of the axe upwards with the other. There was a grunt and the pressure against me fell away.

Arms came around me from behind and I roared and jerked back, trying to slam the back of my head into the bridge of a nose, but I couldn’t reach. I struggled blindly for a second, then I scraped the heel of my trainer down my captor’s shin, reverse-punched him in the nuts, and when he leaned forwards in pain, then I headbutted him.

I immediately swung back to Reece. Will was there. He fought with vicious precision, but two others were closing in on him. I didn’t stop to wonder where Grady was or whether Curtis had reached us. I hollered into the wind and jumped.

A fist smashed into my face and my nose cracked. For a moment, pain really did blind me. An explosion of warm blood covered my chin and neck, and I swung the axe wildly, felt it stick and heard a scream.

Were we the only ones who were armed? Could we be that lucky?

I staggered sideways as a gust of wind hit us. Someone was bowled off their feet, there was a yell of surprise and another person thudded into my leg, not quite knocking me over.

A burning line of pain drew across my right bicep and blood splashed in the edge of my vision.

I kicked out wildly and the boy who had stabbed me buckled. My eyes refocused on Will, just as the skinny lad from Curtis’s team reached him and aimed a karate chop at the back of his neck. Will jerked.

I had to get to him. But before I could move, Curtis appeared. He punched Reece’s teammate to the ground, then grabbed me one-handed by the throat. With his other arm, he easily held my axe away.

“What was in that geocache box?”

I struggled, but he was bigger and stronger. Beside me Reece had Will locked in a sleeper hold. Somewhere Will had lost his pick.

And where was Grady?

It was Lizzie who came to the rescue. She sprinted in, low and fast, leaping over a lad who was rolling on the ground. She ran past me and, to Reece’s surprise, rammed her knife into his forearm. He yelled and released his hold on Will. Lizzie released the knife, jumped out of reach and raced for the beacon. Reece followed her, crimson-faced.

Curtis shook me and spat in my ear. “What was in it? Tell me!” His grip tightened and I had to fight for breath. The world started to fade and I lolled.

Will bashed Curtis over the head with doubled fists until he let me go, and shoved him at the cliff edge. Then he took my arm and ran after Lizzie.

I stumbled after him. “There’s nowhere to run to,” I gasped through my flattened nose.

“Here.” Grady’s voice was faint over the still-rising gale. “This way.” He was gripping the beacon with one hand and Lizzie was backing towards him.

Reece was striding forward, smiling and cracking his knuckles. “I’m going to enjoy this.” He wasn’t running; there was no hurry. He knew there was no escape.

I tried to shake Will off and go for Lizzie, but my legs collapsed.

I struggled against my brother’s hold. “Help Lizzie.”

Will shook his head.

“Grady!” I choked. I realized I was still dragging my axe, the head bouncing on the ground as we stumbled nearer.

Reece pulled the knife out of his arm and flourished the blade at Lizzie. “Do you know where I’m going to put this?”

Lizzie tripped, falling over the edge of the beacon and landing on her elbows. As Reece finally leaped for her, she scrambled desperately backwards.

Then Carmen appeared. She rose like a demon from behind Grady, clutching her knife.

Lizzie gasped. “No, Car!” But there was no halting her.

Taken by surprise, Reece staggered back, far enough for Will to grab hold of him with one arm.

I dropped my axe and grabbed on to Reece’s shirt, helping Will to hold him. If I let go, he would hurt Carmen and Lizzie.

Reece kicked backwards, but in a second Carmen was on top of him, screaming. He tried to use the knife in his hand, but Will kept a tight hold of his elbow.

“Get off me,” he growled.

Carmen wailed in his ear, her hair lashing in the gale, her eyes wild. Then she stabbed him in the right cheek. She yanked the knife free as he yelled and a fold of skin dangled over his face, revealing gum and tooth.

I stared in horror.

Reece howled, then shouted for help. “Boys!”

But one of them was trying to pull his mate back on to the clifftop. Curtis and the skinny boy had another cornered, and the fourth was too far away, fighting the wind.

Carmen stabbed again; this time she took off half of his ear. Blood stained his collar.

He screamed his shock and rage. “I’m gonna kill you!”

Carmen thrust her stump into his face and stabbed again, this time sticking the blade between his collarbone and throat. A great spurt of blood gurgled up when she pulled the blade. It was hot where it splashed against my bare skin.

Stunned, I let go and fell to the ground, but Will held on. Carmen stabbed again, into Reece’s shoulder, then again up under his jaw.

“Carmen,” I whispered. “Stop! Please!”

Reece fell to his knees. Even though Will let him go, he didn’t rise again. Carmen’s breath was a rasp now and tiredness slowed her arm, but she kept on stabbing. It was hard for her to pull the knife out each time, but Reece wasn’t even trying to push her off him any more. He collapsed full length and lay still. His eyes bored into mine, a tear ran down one of his cheeks and suddenly, as his life ebbed away, I saw that he really wasn’t any older than I was after all.

“Enough!” Lizzie hauled Carmen to her feet, holding her tightly in a hug from behind. Carmen panted and shook as she stared at the dying boy.

Then she spat at him.

“You killed him!” Reece’s mates were running to get to us. Curtis too.

“This way, hurry.” It was Grady. I looked up. Will yanked me to my feet. Instinctively, I grabbed the haft of the axe as I was hauled past.

“Come on, Ben – I’ve got to close it!”

Close what? My head was pounding, blood was streaming from my nose, my eyes were swollen – definitely blackened – and the wind was screaming. Carmen and Lizzie reached Grady first. I closed my eyes, and when I opened them, they’d gone. Was I hallucinating again?

Will spun me round and shoved the small of my back. I rammed into the side of the beacon, then Grady grabbed me and pulled me round, past the stone base. I gaped. The stone beacon, the last geocache box, had been opened.

Will was on my heels and then … I was lurching downwards.

I blinked, trying to clear my eyes of Reece’s blood. Will propelled me from behind and I stumbled further down – disoriented, confused – the wind cutting out as I dropped below ground level.

“Lizzie!” Grady was screaming. “Lock it!”

Lizzie pushed past me and I could hear furious yelling from above, a booming sound and the whirring of a lock engaging. Then total darkness.

Two ticks of my heart, two seconds, then lights came on.

The wind had gone, but my ears rang. I could hear the detonation of each heartbeat, feel the blood pounding in my nose, my face, my arm, my legs. I was bruised, hurt, bleeding. Slowly I raised a hand, but Lizzie was there first, gently wiping the blood out of my eyes.

I looked at her. Her glasses were cracked.

Then I looked at Carmen and Grady, and finally at Will. We were all dazed and shaking.

I looked down.

“It’s a staircase.” I blinked.

“Carmen and I – we solved the last checkpoint box,” Grady said. “When we finished the puzzle, the beacon opened automatically. I guess we have to go downwards.”

“And quickly.” Lizzie looked up at the door closed above us. “Before Curtis and the others work out how to get in, too.”