Lights flickered in front of me, and I groaned, lifting a hand to my forehead groggily. Something shuffled beside me, and low, murmured voices met my ears. I tried to open my eyes properly, but the harsh light hurt too much. I twisted with the sudden feeling that I must have been lay in bed. Sheets tangled around my legs as I buried my face into a pillow, attempting to slowly adjust to the light.

"Miss Grace?" a soft voice came. "Miss Grace, can you hear me?"

I didn't reply. Yet again, I wasn't sure if I trusted myself not to throw up. It was becoming so much of a habit, I ironically felt sick just thinking about it.

A sigh of frustration sounded, a little further away. "This is useless, just let me-"

"No," someone else barked sharply, and the man's voice made my head rattle painfully. I flinched, pushing myself further into the pillows with a tight frown. There was a moment of silence. "You shouldn't even be here," the third man continued. "If Zeus knew-"

"Fine," the second guy snapped, sounding oddly like a moaning child. "I'll leave. But you know she'd be on her feet quicker if I helped."

The first, softer voice sighed heavily. "I believe Dionysus is right," he said carefully. "I'm sure you could heal Acacia better than anyone-"

"You know I could," the guy interrupted.

"Be that as it may," the first continued. "Perhaps she is better off without your . . . err, help, at least for the time being."

A heavier silence followed this time, and I couldn't help it anymore. I needed to know what these people were talking about. I didn't even know who they were. Ignoring the pain in my head, I rolled back onto my back with a wince, and opened my eyes.

"Miss Grace?" the first man asked again, and a door slammed to the side. I flinched again, glancing between the two men left in the room. The first one was sat in a wheelchair beside my bed, his expression concerned and worried. He was a middle-aged man, with eyes that seemed a thousand years old. He smiled as I met his gaze cautiously. "It's good to see you awake, Miss Grace. When we saw all that blood . . ." He trailed off, as if he was remembering something he wished he could forget. "Well, we thought the worst for a moment."

"Yes, yes, all very touching," the other man sighed. He was a short, plump man, with a slightly taunt face and unfocused eyes. His black hair was so dark, it looked almost purple, and he wore a horrible print shirt that made me think of seriously embarrassing Dads at the beach. He sighed, glowering at me. "Welcome to Camp Half-Blood, Acacia Grace. Don't expect me to be happy to see you awake. One more demigod to keep in line."

I stared at him in disbelief for a moment, but decided it was probably best not to argue. "Erm, was there someone else in here a minute ago?" I asked cautiously, clearing my throat with another wince.

The first man shifted in his wheelchair, glancing cautiously at the other. He just snorted and strode out of the room, muttering about curiosity and cats. The guy in the wheelchair sighed. "Yes, there was, but it's nothing to worry about," he said, his expression implying the exact opposite.

I took a deep breath, pushing myself up slowly and scanning the room I was in. A lot of beds seemed to be spread out, each with clean sheets and a small table laid out with a bottle of green liquid and glass sat beside them all. "Where am I?" I blinked.

"This is the infirmary," the man told me. "In the Big House at Camp Half-Blood. You've been here for four days. Even Mr Jackson woke before you did."

I stared. "Percy Jackson is here?"

The man nodded, smiling wearily. "After the incident at the museum, it was only ever going to be a matter of time before the two of you ended up here. To be honest, I was surprised to see you there. It seems someone failed to warn me your school was on a trip."

"Wait," I frowned. "You're that teacher Percy was with, right? I thought I recognised you!"

He chuckled, stretching out a hand. "My name is Chiron," he told me. "The other man you just saw is Mr D, the camp director."

"Short for Dionysus?" I guessed, and thunder rumbled outside.

Chiron grimaced. "Mr D is fine," he corrected. "Names have power. It's a bad idea to address gods, or even monsters, by their real names. Unless, of course, you find yourself in a direct conversation with one, which is somewhat rare."

"Is that a good thing?"

He smiled tightly. "Most of the time, yes." He took a deep breath, wheeling himself toward the end of my bed. "Do you think you're up to a walk? There is a lot we need to talk about."

I remembered the dreams I had had, and the things Meg the monster had told me. Pursing my lips, I nodded and swung my legs off the bed, cautiously getting to my feet. I swayed slightly, and Chiron flinched, but I took a deep breath and composed myself. "I'm fine," I told him uncertainly. His eyes shone as he nodded at me, leading the way out of the room.

Outside, we stepped onto a porch that wrapped all the way around the house. Though the sun shone brightly in the sky above me, a shiver ran down my spine as the summer breeze drifted around me. I gazed out over the valley, where kids of roughly my age were playing basketball, or practising at an archery range, or launching javelins through the air, or trying to kill each other with swords.

It took me a moment or two to process everything, but when I turned back to Chiron, I almost fainted again.

The wheelchair had gone, and he was stood straight and proud. But, just like the boy I'd seen Percy Jackson dragging up the hill, he didn't have human legs. Unlike the boy however, Chiron was half horse. His upper body was still that of a man, exactly as it had been in his wheelchair, only now, where his hips and legs were supposed to start, there the body of a white stallion.

He smiled when he saw me blink in shock, flicking his tail. I shook myself, trying to get to grips with everything, but moving so much so quickly made me stagger. Chiron started forward to steady me, but someone behind me had already taken my elbows, steadying me.

"Acacia," Daniel winked, smirking slightly at me as I composed myself again and pulled away from him. "You're up."

"For now," I commented with a gulp. "Can someone please explain what on Earth is going on? You're. . ." I turned back to Chiron, unable to stop myself pointing at his half of a horse.

Fortunately, he chuckled at me. "A centaur," he said. "Yes."

I frowned. "Are you . . . are you actually the Chiron? As in, the one from the Greek myths?"

He laughed again, nodding. "I suppose you could say that. Although, I don't think they're myths if they are real stories, do you?" I let out a stunned whimper in reply. Something about me seemed to make Chiron nervous, as though he thought if I couldn't handle this, I was in for a serious surprise in a moment. Something told me he was right.

"Do you want me to show her around, Chiron?" Daniel offered.

"No, no," Chiron grimaced. "I think I'd better do it. But if you could go and let Luke know, she'll need a space in Cabin Eleven tonight." Daniel nodded, winking at me once more, then stepping off the porch and racing away.

"Erm, Chiron?" I started with a gulp. He raised an eyebrow at me. "Is everything you're going to tell me this hard to digest?"

He stared at me, and a look of such sadness passed over his face, I thought I might have actually started crying on the spot. "Acacia," he breathed, his voice so soft I could barely hear it. "There is a lot you must know, and none of it easy. It will be hard, but you must know. I fear your life may depend on it."

I didn't reply immediately, and when I did, I couldn't stop my voice quivering. "So, that's a yes then?" He smiled sadly, placing a hand on my shoulder and steering me toward the hill Daniel and I had climbed four days ago.

He didn't say anything until we reached the top, a place I didn't particularly want to be. I was pretty sure the red patch I could see was actually my blood. My hand flinched toward my neck again, to find that the locket was still wrapped securely in place. It surprised me a little. I remembered one of the guys who'd found Daniel and I commenting on it. Hadn't he thought to take it back? I made a mental note to found out who it was and return it.

Chiron had stopped by the large, pine tree, staring at it a distraught look I didn't understand. His eyes flicked back toward me, and he sighed heavily. "Acacia, do you remember anything about your childhood?"

My throat closed up, and I dropped my gaze to the ground with a small shrug. "Flashes," I admitted quietly.

Chiron waited patiently for me to elaborate, but I couldn't. His lips pursed. "You were only four years old when your older sister, Thalia, ran away from home. Do you remember that?"

An image burst into my head at the mention of Thalia; she was about nine years old, with spiky black hair and electric blue eyes. I gulped hard. "Yes," I admitted, still not looking at him.

He let out a low breath I hadn't realised he was holding back. "And you remember nothing after that?" I shook my head. "Acacia, your father wiped your memory for a reason. It's hard to explain, but you and your sister were in an enormous amount of danger. Part of the reason she left was to protect you."

"Where is-" I cut off, realising that in this situation, there was only one possible outcome. The look Chiron gave me was unmistakeable. I had to gulp hard to find my voice again. "W-What happened?"

He took a deep breath. "Thalia met two others on her journey," he said quietly. "Annabeth Chase and Luke Castellan. Both of them were there the night you arrived. They came here with Thalia, but when they got here, the three were overrun with monsters. She . . . she sacrificed herself to save the others."

I didn't realise there were tears in my eyes until they were streaming down my cheeks. On automatic reaction, I sniffed loudly and wiped the tears away with the back of my sleeve.

Chiron sighed, staring back at the pine tree again. "Her father took pity of her as she died and turned her into this tree. It now protects our borders and stops any monsters from attacking us."

I wanted to scream. I wanted to yell about how I didn't care about the borders of camp. I wanted to point out that they managed perfectly fine before, and that I needed my sister back. I wanted to shout that this was our fathers fault, if our father was even the same man. I wanted to kick, scream and cry until I couldn't move anymore.

But I couldn't move to begin with. I couldn't even speak. I just stared at the pine tree in front of me, stood tall and perfect against the night sky, tears streaming down my cheeks.

Chiron's eyes bored into me, and his expression looked that distressed, I wished he'd look anywhere but at me. "I'm sorry, Acacia," he mumbled carefully.

I shook my head at me, blinking furiously.

He hesitated, then stepped closer and patted my shoulder awkwardly. "Acacia, I – there is more that you should know, but if I want me to leave you be for now, to grieve, I-"

"No," I managed to choke, sniffing loudly. "Just g-get it over with."

I thought he might actually cry as he looked down at me, but he nodded once and cleared his throat. When he started talking, he said everything quickly and without emotion, as though it was easier for us both that way. He was right. "Four years ago, after Thalia had died, you . . . you were hunted down. Lord Hades – he took great insult at your birth. Your mother, who had already lost t-one of her children, was very reluctant to see you leave. Out of family loyalty and love for your mother, you remained at her side. Unfortunately, you were attacked a lot because of it. No one believed you could last for three whole years alone like that. Eventually though, you were kidnapped and taken to the Underworld. No one knows what happened down there, but whatever it was . . . your father was furious. Persephone managed to convince Hades to release you to avoid a war, but Zeus demanded your memory be wiped and for you to be sent out of the country. The rest, I'm sure you remember."

I tried to talk, but I couldn't find my voice. All of what he said seemed to hold some sort of meaning to me, but I couldn't remember. After hearing all that, I wasn't sure I wanted to.

And still, the only thing I cared about was Thalia.

Again, Chiron patted my shoulder with a loud gulp and turned back down the hill, leaving me only. I didn't move for a long time, and when I finally did, my hands were shaking at my sides. Breaking out into fresh tears, I slumped to the bottom of the tree and pulled my legs up to my chest, letting my hair fall in front of my face.

I wasn't sure how long I sat there, but my throat had long since run dry and my eyes were sore and irritated. But no matter how bad it made me feel, I didn't stop crying. I cried for Thalia, for the mother I couldn't remember, the father I couldn't help but hate, and the younger me, who put up with so much just for it all to come to such a horrible ending. I cried for things I didn't realise had upset me so much, like sudden longing to run back home to Scotland, or the irritating urge I had to clamp my hands around the locket that didn't belong to me and never let go.

I didn't stop or look up until I heard someone sit down opposite me with a soft thump. Even then, it took a few minutes before I felt any desire to move.

The guy stared at me with an expression I couldn't read. He looked about nineteen, with salt-and-pepper hair, piercing blue eyes and a sporty look. He wore an orange top that read CAMP HALF-BLOOD, and combat shorts that stopped at his knees. A long scar ran down one of his cheeks, from the bottom of his eye to his jaw line.

I sniffed, wiping my eyes and straightening out. "Can I help you?"

His lips twitched sadly. "You're a lot like her, you know," he muttered, jerking his head toward the tree behind me. My lips pursed. "Not just in looks, either. Dan said you were softer than he thought you would be, a lot more laid-back. But you look like you can be just as stubborn when you have to be."

I frowned at him, about to demand who he was, when it clicked. "You're Luke Castellan," I told him, and he laughed, nodding.

"Yeap, afraid so," he grimaced. "And you're Acacia Grace, Thalia's little sister."

"Acacia's fine," I said, a little shortly.

He smiled, his eyes flicking upward slightly, staring at a spot above my head. "Can I presume you have the same father?"

I found myself scowling at him, pushing myself to my feet and dusting myself off. "Presume what you want," I replied coolly. "I don't really care."

As I started back down the hill, Luke leapt to his feet and followed me. "Hey! How about a tour of the camp?"

"How about you leave me alone?"

Luke winced. "You realise I'm the Counsellor of your cabin right now?"

"Don't care."

"You probably should." I pursed my lips. Thing was, I probably would be in awhile. Right now, I was too angry. "Acacia, I get that this is hard-"

"No!" I almost screamed, wheeling around and pushing him back so hard, he staggered, catching himself with one hand before he collapsed to the ground. Some of the other campers went rigid, turning to gawp as us. "You have no idea how hard it is. Don't even pretend to get it! And the last thing I want is you anywhere near me. I'm not Thalia, and I never will be."

"I never said you were!" he breathed, wide eyed. "Look, I'm sorry if I upset you, but-"

"Don't you get it?" I spat. "I don't want to talk to you, I don't want to know you, and I certainly don't need your sympathy, so back off!"

He blinked in amazement. "Acac-"

Before he could say anything else, someone hurriedly slipped between us. "I don't think that's a good idea," Percy Jackson grimaced at him, hovering as close to me as he dared. Luke glanced between the two of us, then held his hands out in surrender. Percy peered at me cautiously. "Erm, how about I show you to the archery range? You know, work off some . . . emotions." He said it like he was scared to tell me I was angry. Not trusting myself to speak, I nodded once and followed him away, ignoring the stares I received as we moved.

It didn't take long for us to reach the archery range, but I'd already started to calm down as we came to a halt. Sighing heavily, I leant against the fence, casting a sideways glance at Percy. "Thanks," I muttered. "You know, for-"

"Forget about it," he dismissed. He hesitated a moment, then frowned at me in surprise, like he'd just realised what he'd said. "I didn't mean . . . you know, with your memory and everything-" He cut off in surprise when I burst out laughing.

"I'm sorry," I breathed between chuckles as he blinked at me. "Oh, that wasn't funny."

His lips twitched in confusion. "Err, okay." I took a deep breath, calming myself down and staring across the archery range at the target. At the sight, my hand flinched toward the locket around my neck.

Gulping hard, I turned back to Percy. "Actually, you don't know who else was on that hill when I got here, do you?"

He frowned slightly. "Erm, Annabeth Chase was there," he commented, and my stomach twisted.

"Not her," I said before I could think about it, shaking my head.

Percy's eyebrows rose, but he didn't argue. "Other than me, you, Grover and Daniel, there was only Annabeth, Luke and . . . err, Lee, I think. Lee Fletcher. Annabeth said he was one of Apollo's kids."

"Do you know where I can find him?"

He shrugged. "Apollo's cabin, I guess. If not, someone there might know where he is."

I blinked at him, pulling a face. "Apollo's cabin?"

"I'll show you where it is, but you should probably get someone to show you around," he grimaced. I didn't say anything, turning and following him away from the archery range again. He pointed out a couple of the important places, like the sword arena, or the dining pavilion. Other than that, he didn't seem to know where anything else was.

Finally, we came to a large common area, where cabins of all different shapes and sizes were arranged in a 'U' shape around the edge. Percy was just explaining how each one housed the children of a different Olympian god – unless the one in question didn't have children, in which case it was purely honorary – when someone yelled something to the side. The two of us spun, and I blinking in surprise when a huge, overly muscular girl marched toward us furiously. Her hair was pulled back tightly, and I was pretty sure that Percy and I put together couldn't have matched the sheer size of her muscles.

"You the new kid?" she barked at me, and Percy snorted next to me.

"Want to go down that road again?" he asked with a small smirk. I didn't understand what he meant, but the girl literally trembled with anger.

"Push me further," she warned through her teeth. "Just a little, I dare you."

Percy opened his mouth, but I held out a hand and shot him a silencing look. "Yes, I'm the new kid," I told her. "Is there something I can do for you?"

She scoffed like the question offended her. "You? Why would I want anything from you? All I'm saying is keep away from the punk next to you, unless you want to end up in the same situation."

I blinked, and Percy's jaw locked. "Thanks for the warning," I said slowly. "But if you don't mind, I have someone else to talk to."

The girl's eyes flashed dangerously, but I turned and walked away. Fortunately, the Apollo cabin wasn't hard to pick out. It was made of a similar golden metal as the locket I was wearing, and the light shone off it just as much. Percy kept in line with me, smirking slightly "You realise she's gonna hate you now, right?"

"Who is she?" I frowned.

He shrugged. "Some Ares camper who likes to bully new kids."

I couldn't help smiling as I raised an eyebrow at him. "Really? Dare I ask how you know that?"

His smirk widened a fraction, but something that looked like worried uncertainty flickered across his expression. "Not really sure how to explain that one," he admitted with another shrug. "Besides, shouldn't you be finding Lee?"

My smile faltered, but I nodded and stepped closer to the overly-bright cabin. Stopping outside the door, I raised a fist and knocked cautiously.

A boy about fifteen years old pulled the door open, a little flustered. He had ruffled, sandy hair and bright blue eyes, his skin heavily tanned. Like all the other kids here, he had an athletic build, wearing an orange CAMP HALF-BLOOD shirt. He frowned a little as he looked at me, then shook himself as though he realised what he was doing this.

"Hi," he greeted. "You new?"

I nodded. "Yeah. My name's Acacia. I'm looking for Lee Fletcher?"

The boy's eyes widened at the sound of my name, and his eyes automatically flicked down to the locket around my neck. "He's out in the forest with a few others, being an idiot, as usual. Did you want him for anything in particular?"

My hand flinched toward the locket again, but I shook my head. The boy's eyebrows rose, and he sighed heavily. "Look, if this is about the locket, forget it," he grimaced. "You killed three hellhounds the other day, one after sustaining a blow to the head that would have knocked out most half-bloods for weeks. If ever there was someone that earned the right to use it, it was you."

I stared for a second, oddly relieved. "But . . . there was only three," I said slowly.

His lips twitched into a smile. "Ever heard the saying it's quality, not quantity? Besides, it's not my call. It's not even Lee's."

"Then who?" I asked.

He smirked, pointing at the sky. "Orders from above. Congratulations. You just impressed a god."