“Ben needs to eat, drink and rest.” Lizzie took control. “We can’t set up camp right here – other teams could be arriving any time. Will, Grady, can you guys go to the bottom of the hill and pitch somewhere on the east slope? Light a fire and get some food started. Carmen and I will bring Ben.”

Will and Grady shouldered their packs, then hung mine and Lizzie’s on their fronts, sandwiching themselves in equipment.

“We can’t take Carmen’s,” Will warned as Grady grunted and bent his knees.

Carmen put her own rucksack on. “That’s fine, querido amigo, I am not walking wounded. I’ll set up my own bivvy when we get down.”

Will nodded and turned away. “Don’t forget to relock the box,” he called as they started downhill.

I watched through foggy eyes as Lizzie picked up the small box that now contained my tooth. She dropped it back inside the checkpoint box and closed the lid. Then she pressed her thumb down on the screen. The lock clicked.

“I feel bad,” she said after a moment. “We’re leaving the next group with the same problem.”

“What do you think they’ll do?” Carmen asked. She was wearing a green jumper. When had she dressed?

“Hopefully they’ll give up.”

I pictured other people pulling out their teeth because of one stupid dirty trick. I swallowed and the taste of more blood made me retch.

“Poor baby.” Lizzie stroked my forehead and I leaned towards her.

“Can’t rest here, chico.” Carmen pulled me on to my feet. I staggered and Lizzie steadied me. She had her crutch under her arm. “We just need to walk downhill,” she murmured encouragingly. “One step at a time.”

The ground beneath me appeared spongy and I staggered and sat down hard, almost pulling Lizzie off her feet.

“We’re going to have to leave it a little while,” I heard Lizzie say. “He’s off his face and losing blood. We’ll be lucky to get him moving in a straight line.”

“He threw up most of what he took,” Carmen replied seriously.

“But how much got into his bloodstream before that?”

Lizzie sat next to me and put her arm around my shoulders. “I think the bleeding’s slowing,” she said. “Come on, Ben.”

“Water,” I whispered hoarsely. I wanted my mouth cleaned out.

“Not yet.” Carmen squeezed my hand. “Your gum has to clot first.”

Lizzie and Carmen hauled me back to my feet. I swayed. Little lights burst all around me and I held my hand in front of my face; it left a trail of lights like fibre optics.

Carmen sighed and put her shoulder underneath mine. “I know you did this partly for me, chico.” Her voice was low. “I’m going to make sure we win this.”

“He did it for me, too,” Lizzie said. “He knows I want to pay off our mortgage.”

Carmen stared at Lizzie over my head. “Why do you want to do that? Your parents aren’t short on money, are they?”

Lizzie looked at me and then at Carmen. “Don’t tell the others, but Dad’s not well. It’s his prostate.” She swallowed. “He needs to give up work, but he won’t until the mortgage is paid off.”

Chica! I didn’t know. Your poor papi.”

“It’s OK.” Lizzie shrugged. “Mum’s looking for a full-time job, but at her age… All the interviews she’s got have been for low-paid positions.”

“And you haven’t even told Ben?”

Lizzie shook her head. “I didn’t want him to worry … and…”

I tried to lift my hand to comfort her, but my arm felt like spaghetti and there were moths flying around our torches. They looked like fluff, leaving puffs of dust in the air. When I looked back at Lizzie, she was talking again. What had I missed?

“…our relationship isn’t like that. I mean, he’s my best friend. Apart from you, of course. But we don’t talk about family stuff. He’s had something going on at home since before his dad left, but he’s never talked to me about it – he shuts me out every time I try to mention it.”

“So you don’t talk to him?”

“Not about Dad’s illness, no.”

“Well, he knows now.”

Lizzie laughed. “I don’t think he’ll remember much about this at all.” She caught my hand. “Come on, Ben. We’ll try to get a bit further this time.”

At first each step seemed like a huge effort, the three of us half-walking, half-reeling through the darkness. Carmen held the torch so that we could see the ground, Lizzie tested the footing with her crutch.

Her dad was sick and she hadn’t told me. She felt like I didn’t confide in her, so she didn’t confide in me. I hadn’t known that by holding back my own problems, it would hurt us. But it had.

After a while my movements started to blur, as if the ground were flying under me. Then the slope evened out and it was as though all the stones wanted to trap my feet.

Carmen and Lizzie were panting; Carmen lurched under my weight, but I couldn’t move without her guidance. “Sorry,” I said. “Sorry, sorry, s—”

“It’s not your fault, chico.” Carmen grunted as my foot caught on another rock. “You’ll feel better in the morning.”

A fire glowed in front of us.

“Will?” Lizzie called. “Come and help.”

Mum was shrieking. “Have you seen this?”

I looked up from my spellings. She was holding Will’s bag in one hand and a letter in the other.

“Dean, have you seen this?” Mum was still yelling.

There was a thumping upstairs as Dad left his study. He glanced at me as he came into the kitchen, then at Will, who was standing in a corner by the door.

“What’s up?”

What’s up? What’s up?” Mum mocked. “That interfering cow at the school.” She shook the paper. “She made Will see –” her voice lowered – “a counsellor.” Like it was a dirty word.

“Without our permission?” Dad frowned.

“It’s a school thing,” I said cautiously. “Miss Clark comes in every Wednesday and does Nurture Group with some of the…” I trailed off.

“Yes?” Mum said dangerously.

“Some of the kids who…” I tailed off again. “Kids like Norah,” I said.

Norah wore bottle-thick glasses and threw screaming tantrums five times a day.

“The more challenging kids?” Dad asked.

I nodded.

“And now they want us to have an appointment with her.” Mum crumpled the letter in her fist. “How dare they!”

Dad started forwards. “Can I see?”

Mum snatched the letter back. “Why?”

“I want to see what it says.”

“It doesn’t matter what it says. That Clark woman thinks there’s something wrong with my boy. I’ll sue.”

Will’s eyes flickered to me.

“Well,” Dad said slowly, dragging his fingers through his flop of bright red hair, “she is a professional… Maybe we should—”

“Are you insane?” Mum shoved the letter into the kitchen bin, pulled out the bin bag, tied it tightly and marched out of the back door. We all watched as she slammed the bag into the wheelie bin then strode back in. “There, gone.”

“But the issue hasn’t gone,” Dad said softly, looking at Will.

Mum trembled. “You’re calling my boy an issue?”

“Something must have happened to trigger this.” He looked at me. “Ben, did something happen at school this week?”

I tried not to look at Mum, who was tapping one foot and glaring at me.

“Ben?” Dad took my chin. “Tell me.”

I spoke in a whisper, not meeting his eyes. “He cut Anna’s ponytail off.”

“He what?” Dad stared.

“Anna wouldn’t give him her crisps.”

I was going to get in so much trouble. Mum’s eyes were boring into me and Will had his arms folded, expressionless.

“Did you know about this, Carrie?”

Mum sniffed. “I went into the school. It was all sorted out.”

“Why wasn’t I told?”

“It was sorted out.” Mum’s own face had lost all expression. She looked exactly like Will.

“What happened, exactly?” Dad asked me. He wouldn’t let me look at Mum.

“She should have given them to him,” I muttered. “He asked nicely.”

“But it was Anna’s lunch,” Dad said gently. “She didn’t have to give it up if she didn’t want to.”

“But she should have,” I shouted. “Everyone knows—” I clamped my lips together.

“Everyone knows what?” Dad pressed.

“I want to go to my room,” I begged. My feet jittered against the chair legs.

“Leave your son alone,” Mum snapped. “Let him finish his homework.”

“What does everyone know?” Dad asked again. I swallowed.

Dad stood up. “It’s OK, Ben.” He looked at Mum, then at Will. “What does everyone know?”

It was Will who answered. “They know they should do what I want.”

“… or else,” I whispered.

“We can deal with this at home,” Mum said. “He doesn’t need a counsellor. He needs his family. I’m calling the school. If that woman comes near Will again, I’ll ruin her!”

I opened my eyes. My gum throbbed like it had a spike in it. I touched the hollow with my tongue and tried an experimental swallow. I no longer tasted blood. That was good. I rolled over with a groan. My head was killing me and for some reason I felt sad. But why? I searched my memory. It was full of holes.

I was tired, but I wasn’t getting back to sleep without a painkiller. I reached for my torch and my hand knocked over a water bottle. It reminded me of the last thing Lizzie said to me before I passed out. “I’m leaving some drugs right here. Take them if you need them.”

Blindly I felt around until I found the little packet. Without switching on the torch, I popped two pills out of the foil, opened the bottle of water and took them gratefully. I was glad I hadn’t needed the torch – my eyes ached. Every muscle was sore and I was hungry, but I could feel sleep pulling me back under. My body wanted to heal.

Before dreams took me, I sensed movement and fought my eyes back open. In the darkness, a figure was moving, rustling among the backpacks. Who else was awake?

“Grady?” I whispered.

Then I fell asleep.

Towards the end of March, Will officially joined me in Year Two and he asked to bring home the class pet: a bright orange guinea pig called Chewbacca. He played the baby card first, appealing to the teacher with wide grey eyes and a wobbling lip.

“It’s Matthew’s turn,” Mrs Heap said. “You and Ben aren’t on the list for this term.”

And never would be. Mum hated pets and I was sure she’d asked to be excluded from the timetable.

Will retreated, tears unshed. Then he spent the whole day on a charm offensive. Matthew was offered the chocolate bar from his lunchbox, Mrs Heap was given a handmade card that he’d constructed during his lunch hour. It had a picture of flowers on it, and a glued-on heart with the words I luff you Misuss Heep. He could spell perfectly well.

Will put up his hand for every question. At tidyup time he won a sticker and during PE he took the blame when Matthew’s ball went over the fence.

At the end of the day, Matthew went to Mrs Heap and told her that he didn’t want to take Chewbacca any more.

On the way home, Chewbacca bit Will’s finger when he poked him through the cage.

As I slept I dreamed of dead guinea pigs with hair the same colour as mine, and blood. Lots of blood.

I woke to the smell of bacon, coffee and woodsmoke. It was barely light. When I rolled over I saw Grady and Carmen by a smouldering fire. Carmen was slicing open bread rolls with the blade of her Swiss army knife; Grady was poking a pan with a long fork. I was dragged into full alertness by my nose: bacon sandwiches!

Experimentally I lifted my head. It no longer ached. I felt nauseous, though, and my gut clenched like a fist. I wriggled out of my bivvy into the predawn chill and crawled to the fire.

“Ben!” Carmen looked up. “We let you sleep for as long as we could. How are you feeling?”

“OK,” I croaked. “Hungry.”

“Here.” Carmen snagged some bacon from the pile on the plate beside her and slapped it on an open roll. “Eat.”

Grady handed me his coffee. “I’ll make another.”

“Thanks.” I took the sandwich from Carmen and as I took my first bite, I automatically looked for Will.

“It’s his turn for a wash in the river.” Carmen answered my unspoken question. I froze, the sandwich sticking to the roof of my mouth. It was my blood that they needed to rinse away. For the first time, I looked at my own hands. Dried brown flakes followed the lines on my palms.

Quickly Grady handed me a pan of water. “Use this. We can refill it.”

“Thanks.” I put down the sandwich, dunked my hands and watched the water muddy. Then a sound from Lizzie, half a sob, caught my attention. I paused, my hands dripping. There was something about Lizzie, something I needed to remember. I looked around.

She was kneeling by the pile of rucksacks, still in the grey tracksuit she wore to sleep in. Her pixie hair was half-glued to her head.

“I told you mine was at the bottom,” she cried. “I said they’d been moved.”

“Who would move the rucksacks?” Carmen raised an eyebrow.

I frowned as a memory surfaced. “Didn’t Grady get something in the night?” The vision was hazy, part-dream, but I was sure I’d seen him. Hadn’t I?

“Nope. I passed out like a rock. Didn’t move till dawn.” Grady forked more bacon on to the plate. “What’s the problem with the rucksacks, anyway?”

Lizzie turned, her face stricken. “The tooth – it’s missing.”

“It can’t be.” I frowned. “Maybe you moved it…”

Both Carmen and Grady were staring at Lizzie in horror.

Lizzie shuffled back. Her rucksack had been emptied, the contents were strewn around her knees. “It’s not here.” Her voice was dull.

I lurched to my feet. “It has to be!”

“Grady, are you sure you put it in Lizzie’s rucksack?” Carmen looked at him. “Maybe you put it in your pocket by mistake?”

Grady shook his head, but he stood up and started to go through his clothes. “It’s not here. I put it where Lizzie told me – I remember doing it.”

“Check again.” I swallowed. “Check everywhere.”

“You saw someone last night, didn’t you, Ben?” Grady’s eyes narrowed as he turned out his shirt pocket. “You thought it was me, but it wasn’t.”

“I thought I did – but…”

“He was off his head, Grady,” Carmen said gently. “He could have been dreaming … or hallucinating.” She stood and walked over to Lizzie. “Will carried your rucksack for you, chica – it might have fallen out.” She snapped her knife closed and put it in her pocket. “I’ll go back up the hill and see if I can find it.” She stood and ran off.

“The bags have been moved,” Lizzie insisted. “My side pockets have been opened. We’ve been robbed!”

“No.” I clenched my fists. “Carmen will find it.”

“What if she doesn’t?” Grady murmured. “What if you really did see someone?”

“How could they have known where the tooth was?” Lizzie was crying.

Grady swore. “They must have been watching us.”

“From where?” I spun abruptly, scanning the rocks.

“It was dark.” Lizzie rubbed her face.

“In the trees, maybe,” Grady said. “If they had night-vision binoculars, we’d have been clear as day.” He swore again.

“But why would anyone be watching us?” I shivered.

Will strode back to our camp, rubbing his hair with a towel. He heard my question and his eyes flicked over us, drawing conclusions. “They couldn’t get in the box,” he said finally and tossed his towel down on top of his rucksack. “So they waited to see how the next team did it.” He made himself a bacon sandwich and began to eat.

Lizzie put her head in her hands. “They watched Carmen blow on the box, then saw us pulling Ben’s tooth and where I put it. They decided to take ours so their team didn’t have to do the same.”

“It makes sense.” Grady dropped his shirt on the floor. “They’ll be long gone by now, with the coordinates of the third checkpoint and our geocache tooth.”

I sat on a rock. “What do we do?”

We looked at one another. Then Grady groaned. “The way I see it, we have four choices.”

Will nodded. “Someone gives up another tooth.”

“No!” My hands flew to my mouth. “Think of something else.”

“OK.” Grady held up his right hand. “Three options then.” He extended a finger. “One, we give up and go back to the beach.”

Lizzie pressed her lips together. “Or?”

“Two, we keep going, tell the invigilators at the end that one of the other teams stole our first geocache and hope they let us off.”

“We haven’t any proof,” Will pointed out.

“Except Ben’s missing tooth,” Lizzie said.

“All that shows is that Ben’s had a tooth out. It could have happened before we left.” Grady shook his head. “It won’t be enough.”

“Then what’s option three?” Lizzie scrutinized Grady.

“Find those bastards and make them give us the tooth back.”

There was a long silence. I stared at my uneaten sandwich. I couldn’t bring myself to pick it back up.

“Grady,” Lizzie said quietly. “Let’s get real. Between my ankle, Ben’s knee, Will’s arm and your elbow, we’re not going to scare anyone into giving us anything, especially if they’re bigger than we are.”

“And there are eight other teams out there.” I rubbed my eyes. “How do we know which of them did it? We catch up with someone, they deny having the tooth and … then what?”

“It was that team we saw ahead of us – the one with the girl leading them,” Grady growled.

“Probably.” Will crossed his ankles. “But we have no way to be sure.”

“There is another option.” I leaned on my knees. “We carry on as normal, complete the other checkpoints, then, if we get a chance to search someone else’s stash, we get a tooth that way.”

Lizzie rubbed her hair into even spines. “Steal someone else’s, you mean.”

“It’s not ideal,” I admitted.

She sighed. “It makes us no better than the thieves who took from us.”

“It’s our best choice,” Grady said.

“We just need to be on the lookout for opportunities.” Will took another sandwich. “If we find other teams, we can wait for them to leave their bags unguarded.”

“And if we don’t get opportunities?” Grady asked.

Then we decide – give up another tooth or tell the invigilators about the theft,” Will replied.

“OK.” I stood. “Last night was awful, but we found the second checkpoint and I don’t reckon every team did. I’m feeling a lot better this morning. Lizzie, how’s your ankle?”

“Stiff and sore, but I can manage with my crutch.”

“Great! Then let’s get our heads back in the game. What’s the plan for today?”

“Break camp and go.” Lizzie started re-stuffing her rucksack. “We’ve got two more days and five more checkpoints. We should be able to get to three today. One by mid-morning, one after lunch and one this evening. Then six hours’ sleep and the final two tomorrow.”

“With any luck, we’ll overtake the team playing dirty this morning,” Grady said as he collected our rubbish.

“You’re sure you’re up for a hard hike?” I stepped towards Lizzie.

She nodded and grinned suddenly. “The sun’s coming up, it should be a nice day. Let’s make it a good one.”

I laughed as I started to roll my sleeping bag. “You’re right. Let’s have a great day.”

After a few minutes Lizzie looked up. “Hey, guys … shouldn’t Carmen have been back by now?”