Annabeth going missing was entirely my fault.

I was supposed to be protecting the two new demigods until we got them to camp. I didn't mean to fall head over heels for one of them, and certainly not another girl.
But I did.
Bianca di Angelo was three years younger than me–twelve–and my fifteenth birthday had passed several weeks before. She was the second-oldest of the trio.
FIfteen-year-old Theia Black.
Twelve-year-old Bianca di Angelo.

Ten-year-old Nico di Angelo.

We were supposed to be at the dance when everything went wrong.
I frowned at Nico, who was shuffling his Mythomagic cards frantically. He and I shared a love of the role-playing card game. Little did Nico know, it gave a hint as to where his ancestry came from.
Meanwhile, Bianca was muttering Italian to herself. She had shoulder-length, raven hair and startling, grayish eyes. I had warned her about the others that were supposed to be coming–but she hadn't believed me.
Nico had.
Now I was frantically trying to get them both to come with me, instead of just one of them. I sighed, running a hand through my long, blonde hair. I shifted, becoming male.
"Theo," said Bianca finally. "What is this place? What's it called? Who are you really?"
I smirked over at her. "You really ask a lot of questions, don't you?" I asked.
Suddenly, I spotted them.
Half-sisters Thalia Grace and Bex Watcher, along with eight-year-old Celia, my adopted daughter, and my other friends, Annabeth Chase and Percy Jackson.

"Hey!" I wanted to shout, but I knew that there were monsters all around me. So I had to remain in hiding, at least until they spotted me.

Grover Underwood appeared behind them. I sighed in relief. They were all here. That meant that the mission was going to be fine.
"Excuse me," I said. "Bianca, make sure Nico doesn't run off. I think I see some friends."
Percy grinned over at me when I jogged towards him, my dreadlocks bobbing into my eyes. "Are they here?" asked Bex impatiently. Celia hugged me around the middle, and I chucked her underneath the chin affectionately. She giggled slightly.
"Yeah," I said, breathless. "Bianca and Nico di Angelo. Brother and sister. Bianca's twelve. Nico's ten."
I pointed over at them, and sighed. "I told her not to let Nico run off," I muttered. Bianca was dragging Nico away from a gang of giggling girls. "We need to blend in," I muttered.
Suddenly, Mr. Thorn appeared. My hand went to my pocket, in which there was my sword, Firestorm.
"Divinità immortali," I cursed in Italian.

"That's the monster, isn't it," bleated Grover fearfully. I nodded. "Manticore, I think. I've killed at least two of those, but both times I almost died, so…"
I trailed off. Then I looked back at Bianca, who was staring around at the crowd, her eyes searching for me. Thalia appeared next to me. "You fell for her, didn't you?" she whispered into my ear. I blushed red.
"So what if I did?" I snapped.
"She's three years younger than you, Theo," Thalis muttered. I shrugged. "It just…kind of…happened…you know?"
Thalia smirked at me. She pulled Grover onto the dance floor to start dancing, and then was joined by Percy and Bex. Annabeth looked a bit miffed. I had always known that Bex had a crush on Percy, but I didn't know if the feeling was mutual.
Now that Bex was fifteen, though…she had a huge choice coming for her. She would either make or break the world.
Suddenly, I realized something.
"They're gone," Annabeth muttered. She ran off to find Thalia and Grover and Celia, but Bex and I looked at each other, then followed after Percy.
The door lead into a dark hallway. I heard scuffling sounds up ahead. Taking out Firestorm, I crept down the hallway. "Nothing to see here," I muttered to myself. "Just three forbidden children going on a walking trip…"
We came to an opening. The di Angelos were there. Percy edged forwards, Riptide out. "It's okay," he said. "I'm not going to hurt you."
The di Angelos looked at me. "Theo?" Bianca asked, and Percy shot me a questioning look. I hurried towards them. "It's okay," I whispered, helping them up. "This is Percy Jackson, and that's Bex Watcher. I'll take care of the monsters, they'll get you out of here, somewhere safe."
Bex screamed suddenly, and sailed over me. Percy cried out in pain as something sank into his shoulder. He fell to his knees. I was the only one still standing.
"I knew it," I growled. "Manticore."
I whirled around, but gasped as a quill sunk into my throat. Blood spurted from the wound, and my vision went red. "NO!" screamed Bianca, and I gurgled something like "Urghlburghl."
I wrenched the quill from my throat, and then staggered back to my feet, my sword arm shaking a bit.

"Yes, demigods," Doctor Thorn said. "I know who you are."
"Thank you for coming out of the gym," he added, his voice a silky sort of purr. I felt my wound knitting over–as a daughter of Hera, one of my powers was accelerated self-healing. I don't know how that applied to marriage or women, but it was one of my powers.
Another one was the ability to influence people with my voice–otherwise known as charmspeak. I swung my sword at the manticore, but it shot me in the knee, crippling me. Above me, Thorn laughed.
"All five of you will come with me. If you try to run or fight, I will show you just how accurately I can throw."