Blackjack huffed. Ain't either, boss. It's five in the morning. What you still sleeping for?

"How many times have I told you? Don't call me boss."

Whatever you say, boss. You're the man. You're my number one. I rubbed the sleep out of my eyes and tried not to let the pegasus read my thoughts. That's the problem with being Poseidon's son: since he created horses out of sea foam, I can understand most equestrian animals, but they can understand me, too. Sometimes, like in Blackjacks case, they kind of adopt me.

See, Blackjack had been a captive on board Luke's ship last summer, until we'd caused a little distraction that allowed him to escape. I'd really had very little to do with it, seriously, but Blackjack credited me with saving him.

"Blackjack," I said, "you're supposed to stay in the stables."

Meh, the stables. You see Chiron staying in the stables?

"Well… no."

Exactly. Listen, we got another little sea friend needs your help.

"Again?"

Yeah. I told the hippocampi I'd come get you.

I groaned. Anytime I was anywhere near the beach, the hippocampi would ask me to help them with their problems. And they had a lot of problems. Beached whales, porpoises caught in fishing nets, mermaids with hangnails—they'd call me to come underwater and help.

"All right," I said. "I'm coming."

You're the best, boss.

"And don't call me boss!"

Blackjack whinnied softly. It might've been a laugh.

I looked back at my comfortable bed. My bronze shield still hung on the wall, dented and unusable. And on my nightstand was Annabeth's magic Yankees cap. On an impulse, I stuck the cap in my pocket. I guess I had a feeling, even then, that I wasn't coming back to my cabin for a long, long time.

EIGHT

I MAKE A DANGEROUS PROMISE

Blackjack gave me a ride down the beach, and I have to admit it was cool. Being on a flying horse, skimming over the waves at a hundred miles an hour with the wind in my hair and the sea spray in my face—hey, it beats waterskiing any day.

Here. Blackjack slowed and turned in a circle. Straight down.

"Thanks." I tumbled off his back and plunged into the icy sea.

I'd gotten more comfortable doing stunts like that the past couple of years. I could pretty much move however I wanted to underwater, just by willing the ocean currents to change around me and propel me along, I could breathe underwater, no problem, and my clothes never got wet unless I wanted them to.

I shot down into the darkness.

Twenty, thirty, forty feet. The pressure wasn't uncomfortable. I'd never tried to push it—to see if there was a limit to how deep I could dive. I knew most regular humans couldn't go past two hundred feet without crumpling like an aluminum can. I should've been blind, too, this deep in the water at night, but I could see the heat from living forms, and the cold of the currents. It's hard to describe. It wasn't like regular seeing, but I could tell where everything was.

As I got closer to the bottom, I saw three hippocampi—fish-tailed horses—swimming in a circle around an overturned boat. The hippocampi were beautiful to watch. Their fish tails shimmered in rainbow colors, glowing phosphorescent. Their manes were white, and they were galloping through the water the way nervous horses do in a thunderstorm. Something was upsetting them.

I got closer and saw the problem. A dark shape—some kind of animal—was wedged halfway under the boat and tangled in a fishing net, one of those big nets they use on trawlers to catch everything at once. I hated those things. It was bad enough they drowned porpoises and dolphins, but they also occasionally caught mythological animals. When the nets got tangled, some lazy fishermen would just cut them loose and let the trapped animals die.

Apparently this poor creature had been mucking around on the bottom of Long Island Sound and had somehow gotten itself tangled in the net of this sunken fishing boat. It had tried to get out and managed to get even more hopelessly stuck, shifting the boat in the process. Now the wreckage of the hull, which was resting against a big rock, was teetering and threatening to collapse on top of the tangled animal.

The hippocampi were swimming around frantically, wanting to help but not sure how. One was trying to chew the net, but hippocampi teeth just aren't meant for cutting rope. Hippocampi are really strong, but they don't have hands, and they're not (shhh) all that smart.

Free it, lord! A hippocampus said when it saw me. The others joined in, asking the same thing.

I swam in for a closer look at the tangled creature. At first I thought it was a young hippocampus. I'd rescued several of them before. But then I heard a strange sound, something that did not belong underwater:

"Mooooooo!"

I got next to the thing and saw that it was a cow. I mean… I'd heard of sea cows, like manatees and stuff, but this really was a cow with the back end of a serpent. The front half was a calf—a baby, with black fur and big, sad brown eyes and a white muzzle—and its back half was a black-and-brown snaky tail with fins running down the top and bottom, like an enormous eel.

"Whoa, little one," I said. "Where did you come from?"

The creature looked at me sadly. "Moooo!"

But I couldn't understand its thoughts. I only speak horse.

We don't know what it is, lord, one of the hippocampi said. Many strange things are stirring.

"Yeah," I murmured. "So I've heard."

I uncapped Riptide, and the sword grew to full length in my hands, its bronze blade gleaming in the dark.

The cow serpent freaked out and started struggling against the net, its eyes full of terror. "Whoa!" I said. "I'm not going to hurt you! Just let me cut the net."

But the cow serpent thrashed around and got even more tangled. The boat started to tilt, stirring up the muck on the sea bottom and threatening to topple onto the cow serpent. The hippocampi whinnied in a panic and thrashed in the water, which didn't help.

"Okay, okay!" I said. I put away the sword and started speaking as calmly as I could so the hippocampi and the cow serpent would stop panicking. I didn't know if it was possible to get stampeded underwater, but I didn't really want to find out. "It's cool. No sword. See? No sword. Calm thoughts. Sea grass. Mama cows. Vegetarianism."

I doubted the cow serpent understood what I was saying, but it responded to the tone of my voice. The hippocampi were still skittish, but they stopped swirling around me quite so fast.

Free it, lord! they pleaded.

"Yeah," I said. "I got that part. I'm thinking."

But how could I free the cow serpent when she (I decided it was probably a "she") panicked at the sight of a blade? It was like she'd seen swords before and knew how dangerous they were.

"All right," I told the hippocampi. "I need all of you to push exactly the way I tell you."

First we started with the boat. It wasn't easy, but with the strength of three horsepower, we managed to shift the wreckage so it was no longer threatening to collapse on the baby cow serpent. Then I went to work on the net, untangling it section by section, getting lead weights and fishing hooks straightened out, yanking out knots around the cow serpent's hooves. It took forever—I mean, it was worse than the time I'd had to untangle all my video game controller wires. The whole time, I kept talking to the cow fish, telling her everything was okay while she mooed and moaned.

"It's okay, Bessie," I said. Don't ask me why I started calling her that. It just seemed like a good cow name. "Good cow. Nice cow."

Finally, the net came off and the cow serpent zipped through the water and did a happy somersault.

The hippocampi whinnied with joy. Thank you, lord!

"Moooo!"The cow serpent nuzzled me and gave me the big brown eyes.

"Yeah," I said. "That's okay. Nice cow. Well… stay out of trouble."

Which reminded me, I'd been underwater how long? An hour, at least. I had to get back to my cabin before Argus or the harpies discovered I was breaking curfew.

I shot to the surface and broke through. Immediately, Blackjack zoomed down and let me catch hold of his neck. He lifted me into the air and took me back toward the shore.

Success, boss?

"Yeah. We rescued a baby… something or other. Took forever. Almost got stampeded."

Good deeds are always dangerous, boss. You saved my sorry mane, didn't you?

I couldn't help thinking about my dream, with Annabeth crumpled and lifeless in Luke's arms. Here I was rescuing baby monsters, but I couldn't save my friend.

As Blackjack flew back toward my cabin, I happened to glance at the dining pavilion. I saw a figure—a boy hunkered down behind a Greek column, like he was hiding from someone.

It was Nico, but it wasn't even dawn yet. Nowhere near time for breakfast. What was he doing up there?

I hesitated. The last thing I wanted was more time for Nico to tell me about his Mythomagic game. But something was wrong. I could tell by the way he was crouching.

"Blackjack," I said, "set me down over there, will you? Behind that column."

I almost blew it.

I was coming up the steps behind Nico. He didn't see me at all. He was behind a column, peeking around the corner, all his attention focused on the dining area. I was five feet away from him, and I was about to say What are you doing? real loud, when it occurred to me that he was pulling a Grover: he was spying on the Hunters.

There were voices—two girls talking at one of the dining tables. At this ungodly hour of the morning? Well, unless you're the goddess of dawn, I guess.

I took Annabeth's magic cap out of my pocket and put it on.

I didn't feel any different, but when I raised my arms I couldn't see them. I was invisible.

I crept up to Nico and sneaked around him. I couldn't see the girls very well in the dark, but I knew their voices: Zoe and Bianca. It sounded like they were arguing.

"It cannot be cured," Zoe was saying. "Not quickly, at any rate."

"But how did it happen?" Bianca asked.

"A foolish prank," Zoe growled. "Those Stoll boys from the Hermes cabin. Centaur blood is like acid. Everyone knows that. They sprayed the inside of that Artemis Hunting Tour T-shirt with it."

"That's terrible!"

"She will live," Zoe said. "But she'll be bedridden for weeks with horrible hives. There is no way she can go. It's up to me… and thee."

"But the prophecy," Bianca said. "If Phoebe can't go, we only have four. We'll have to pick another."

"There is no time," Zoe said. "We must leave at first light. That's immediately. Besides, the prophecy said we would lose one."

"In the land without rain," Bianca said, "but that can't be here."

"It might be," Zoe said, though she didn't sound convinced. "The camp has magic borders. Nothing, not even weather, is allowed in without permission. It could be a land without rain."

"But—"

"Bianca, hear me." Zoe's voice was strained. "I… I can't explain, but I have a sense that we should not pick someone else. It would be too dangerous. They would meet an end worse than Phoebe's. I don't want Chiron choosing a camper as our fifth companion. And… I don't want to risk another Hunter."