The lasagna was incredible, as usual, but I was here on business. I set down my fork. "So, about that fiasco at camp today. We need to ask you guys about something."

"Big problem," mumbled Percy through his forkful of pasta. "Oh my gods, Mom, you've done it again."

Across the table, Sally Jackson scooped herself, then Percy, another serving of lasagna. "Have some more, then. Annabeth, keep going—what's the problem?"

I slid the photo across the table. "Does the name Riverspawn ring any bells to you?"

Paul and Sally both leaned over to inspect it. I didn't want to see it anymore—I'd examined the photo a million times over since we'd gotten it earlier, burned it into my eyeballs. It was a photo of a girl, maybe 17 or 18, in a Camp Half-Blood t-shirt, lounging on the steps of the Big House. Next to her laid a Celestial bronze sword I'd never seen, gleaming with strange jewels embedded in the hilt. The girl was tall and graceful, with perfect tousled black waves and Percy's Mediterranean good looks. In the photo, she was laughing, but the resemblance was unmistakable: if not for the fact that she could not and must not exist, she could easily have been Percy's twin sister. This was Riverspawn Jackson, the Reason Why I Couldn't Just Have One Normal Day At Camp.

"River Spawn?" Paul frowned. He turned the photo around in his hand, squinting it at different angles, as if the girl in the photo couldn't possibly look the way she did. I knew how he felt. "Did you say her name was River Spawn?"

"Riverspawn, yeah, one word." confirmed Percy. We traded miserable glances. "She calls herself Riverspawn Jackson."

Paul cracked a smile. "Willingly?"

Sally shook her head as Paul passed the photo to her. "I've never seen her before in my life. But Jackson is a common last name, isn't it? Do you think…" She glanced at me, but something on my face made her reconsider. Maybe she could read the extreme existential dread in my eyes. Maybe it was the way my face had been frozen in a grimace the whole night. Either way, she understood: in our world, there were no such things as coincidences.

"We don't know much else," I explained. "Earlier today, she came over Half-Blood Hill, alone, with twenty, thirty monsters after her. She vaporized them all before we got to her. Percy, we didn't see how she did it, did we?"

"Nah." Percy shoveled some more lasagna in his mouth. Now that the summer was here, we didn't get to spend much time at home with Percy's parents, so he was making up for lost time—and lost meals. Which was understandable. But it did leave me to do most of the explaining.

"Anyways, so when we got there, she was lying underneath the pine tree, half-conscious. She told us her name, gave us that photo, and then told us—"

Percy choked down whatever was in his mouth, spreading his arms wide. "My name is Riverspawn Jackson," he said ostentatiously, "and I'm here to save the world! Ask my mother, Sally… she'll tell you everything. Euugh." He mimed passing out. "And then she passed out. And then she disappeared." (He'd workshopped this bit when we were sitting in traffic from Long Island, and so he was very proud of it.)

The reactions rolled in at the same time: I smacked Percy's arm. "Stop grinning so smugly, this is serious."

"She just disappeared?" asked Paul, slack-jawed.

"Her mother? Me?" demanded Sally.

I sighed. "Yup. So we were wondering about the off chance that you could, you know, explain everything." I gestured to the photo. "Ring any bells yet?"

Sally laughed uncomfortably. She passed the photo back to us gingerly, as if it was going to explode. "Definitely not. I can't possibly imagine why she would have said that. It's true she looks familiar, almost like…" She trailed off and shook her head. "No, it doesn't make any sense."

"Oh, honey." Paul slung an arm around Sally and sat back from the table, then looked at us. "Do you think she'll be back? Maybe it was a collective hallucination you all had."

Percy and I glanced at each other. "With our luck?"

"Yeah, she's gonna be back," finished Percy.

I really didn't want to see the photo again, but for some reason I picked it up. "I know it doesn't make any sense, Mom," Percy was saying next to me. "We have no idea what's going on either, but we'll keep you updated…"

I'd spent the car ride examining the confident angle of her hips, her scarless, tan legs, the way her head was thrown back in laughter. Something about the photo itched at me in a way that was so deep, so fundamentally wrong, that the world seemed to lose its resolution a little bit.

I was dimly aware of Percy's hand on mine. "Annabeth?" asked Percy. His voice was a million miles away.

Percy gripped my hand tighter. "Annabeth," he said again, more insistently.

I clawed back to his voice. "Look. Look," I said hoarsely. I thrust the photo at him.

In one of the windows of the Big House, as Riverspawn laughed at an unseen joke, there was a figure reflected. It was blurry and hard to resolve, but I would know that silhouette in my sleep—tall, lanky, messy hair.

"Percy, you took that photo."