THIRTEEN — Mayfair.

Recovering from the battle at Fort Sumter was rough on everyone.

Jason and Percy's cool trick had worn them completely out—apparently, working together to summon a raging storm wasn't something they did everyday. (Who knew?) After Theo returned to the ship and Leo blasted off as quickly as Festus could carry them, Jason and Percy let the storm dissipate, and they collapsed together on the deck, their heads slumped with exhaustion. Theo and May were trying to get them to drink some water when Leo returned from the console with news.

"No sign of pursuit," he told everyone wearily, "but I'm not too keen on giving Festus full autopilot just yet. Not until there's more distance between us and the Romans. Hedge is on controls for now, so if we make a sudden pitstop at an armada supply store, you know why. Still, good news—no pursuit!"

"No sign of land, either," Hazel muttered, looking a little green in the face.

Everyone's heads turned toward the horizon. Sure enough, there was nothing but ocean in every direction. May swallowed thickly. She didn't exactly get seasick—not like Hazel—but her dad always warned her against spending too long at sea, on cruise ships or otherwise. But maybe as a history teacher, that fear was learned; medieval piracy was a topic they covered in her dad's class, and May grew up on horror stories about Blackbeard and the Jolly Roger.

Now, May wasn't worried about pirates, make-believe or not. She didn't think they'd be facing anything as trivial as peg-legs out on the Mare Nostrum—they'd be up against much worse. After all, it was the place where all the real monsters and giants came from. Even the Romans were too afraid to follow them out to sea, and that had to say something.

Apparently Leo picked up on the sudden somber mood. He turned to Theo, patting his tool belt as a fidget. "Find that map you were looking for?"

She nodded, but she looked pale. May wondered what she'd seen at Fort Sumter that had shaken her up so badly.

"I'll have to look into it," was her reply, and that was the end of the subject. "We're headed for Rome now? Any stops along the way?"

"There shouldn't be," Leo assured her. "But we've never known exactly what we're going to be up against until it's staring us in the face, so..."

"And we're probably in worse danger out here than anywhere else," Percy admitted, like it was nothing. He still looked rough, but better now, with Theo at his side. "Keto, the goddess from the Atlanta Aquarium—she's the mother of all sea monsters. She might be stuck in Georgia, but she can still send her children after us. The Nereid I spoke to said to expect an attack."

"Great," muttered Frank.

Jason tried to stand, which wasn't a good idea. May had to grab him to keep him from falling over, and he slid back down the mast to land on his butt.

"Can we get the ship aloft?" he asked Leo. "If we could get airtime, the trip would be shorter and we wouldn't have to face—"

"That'd be great," Leo agreed, "except Festus said the port aerial stabilizer got pulverized when the ship raked against the dock at Fort Sumter."

"We were in a hurry," Theo pointed out. "Trying to save you."

"And saving me is a very noble cause," Leo said, spreading his hands. "I'm just saying, it'll take some time to fix it. Until then, we're not flying anywhere."

Percy flexed his shoulders and winced. "Fine by me. The sea is good."

"Speak for yourself," Hazel said, glancing at the sunset on the horizon. "We need to go quickly. We've burned another day, and now Nico only has three more left."

"We can do it," May promised her. She didn't actually know for sure—and that was eating away at her (she hated not knowing things)—but she could understand how Hazel felt, at least. "We can make it to Rome in three days. Right, Leo?"

Leo nodded along. "Assuming, you know, nothing unexpected happens."

"Well, we've had plenty of luck in that department, haven't we?" Theo clapped her hands together. "Let's all try and get some rest tonight. If we really can make it a night without anything occurring or any attacks, I think it'd be to all of our advantages to use it to catch up on the sleep we've been missing."

"Agreed," said Jason. Then both he and Percy doubled over, groaning, holding their heads. "Did the world just spin upside down for everyone else?"

"I think I'm gonna be sick," Percy agreed unsteadily, his voice muffled, as he was speaking to his lap.

"We should get them to the sickbay," May said, looking worriedly at Jason. She pressed the back of her hand to his forehead. "You guys must have sapped a lot of your energy making that storm."

"It was pretty sick, though, wasn't it?" Percy asked Theo weakly, barely able to lift his head.

She smiled and draped his arm over her shoulder, hoisting him up. "Very sick."

She, Percy, May, and Jason made their way down to the sickbay at a snail's pace, stumbling and dragging each other until the boys landed in their own beds with matching groans. They were knocked out within seconds, but not before Percy could give Theo a goodnight kiss.

Once Jason and Percy were out, Theo made an odd gesture with her hand like she was turning an invisible knob, and the lanterns in the sickbay dimmed as if of their own accords.

"We should get some sleep, too," Theo whispered to May as she led the way back to the corridor.

"Don't have to tell me twice." May stifled a yawn behind her fist and shut the door behind herself. Then she remembered something she'd seen at Fort Sumter—or rather, hadn't seen. "Theo, did you.. Earlier during the battle, did you go—"

"Ah." Theo smiled knowingly. "Invisi-Theo mode? Yeah, I learned how to do that when I was fourteen. Pretty cool, huh?"

"I've never met a demigod who could do that all on their own," May admitted, her voice still harboring a tone of awe. "I mean, Annabeth has her Yankees cap, but that's it. It's really cool. Is there anything else you can do?"

Theo thought for a moment, then shrugged her shoulders casually, like it was no big deal. "I mean, I can shoot a cherry off your head from a hundred and twenty yards away."

May gaped at her. "That's a whole football field!"

"Yeah, well."

"No way," said May, scoffing, shaking her head. "I mean, there is absolutely no way. That's just insane."

Theo simpered, crossing her arms. "Want to test me?"

"Not exactly." May's lips betrayed her by cracking a smile. "I think maybe I can believe you."

Theo exhaled a laugh, reaching up to rub her eyes with the heels of her palms. She sighed. "I really need to get some sleep."

"Oh, sorry," said May, rather awkwardly, sidestepping and letting Theo have space to slip past her. "Don't let me... keep you."

"No, not at all." Theo cleared her throat. She didn't move for a second. Then she nodded and used the path Mayfair had forged for her, heading off toward the cabins, still rubbing her eyes.

"Hey," she called over her shoulder, turning back to face May, "by this time tomorrow, we could be in Rome."

May smiled again, nodding. "Ibi te videre."

Theo stopped in her tracks, a mask of confusion falling over her face. "What?"

"Oh," said May, suddenly feeling a burning sensation in her cheeks. "It's Latin. Nothing. Sorry. It just means 'see you there'. I thought it was funny because—"

"No, that's really cool," said Theo, smiling again. "I didn't know you could speak Latin."

"It's no invisibility," shrugged May.

Theo laughed, shaking her head rather fondly. "Whatever. I'll see you in the morning."

They, in fact, saw each other only a few hours later, when the night was still young and the Argo II was lurching side-to-side in a violent way that awoke Mayfair in a flurry. She barely had time to put on her sneakers—much less change out of her plaid pajama pants and too-big sleep shirt that said F.B.I. (Female Body Inspector)—before the ship was thrown so ferociously to its side that she slid into the wall of her cabin and came to a swift decision that, appropriately clothed or not, she needed to get up to the deck and deal with whatever was attacking.

She ran head-on into Jason in the corridor, and after a brief exchange of whether or not the other was okay, they rushed the deck. Behind them the rest of their friends stumbled up the stairs.

Everyone had their weapons drawn, but when they saw the monster at fault for waking them all, everybody seemed to forget how to move.

The thing was the length of their ship. In the moonlight, it looked like a cross between a giant shrimp and a cockroach, with a pink chitinous shell, a flat crayfish tail, and millipede-type legs undulating hypnotically as the monster scraped against the hull of the Argo II.

Its head surfaced last—the slimy pink face of an enormous catfish with glassy dead eyes, a gaping toothless maw, and a forest of tentacles sprouting from each nostril, making the bushiest nose beard Mayfair had ever had the displeasure to behold.

Just looking at it was enough to churn May's stomach with nausea. The thought of being eaten alive by it was enough to get her moving again.

The main deck was a frenzied chaos. Hedge was running around the mast, trying to find whichever button would blow up monsters. Leo was climbing the deck like a Mexican Spider-Man. Hazel was clutching the rigging, looking dazed and nauseous—a dangerous combination. Percy yelled something about a Shrimpzilla, wielding his sword toward the huge pink thing. Frank was, May guessed, the giant falcon in the sky. Theo was already trying to shoot the killer shrimp using Frank's bow, but her arrows were like toothpicks against it.

All the while, the shrimp reared its ugly pink head and screeched at the demigods, like it was frustrated its midnight snack was putting up a fight.

"How did it get so close?" Theo shouted, hooking her elbow on one of the rail shields so she didn't go flying into the mouth of the beast.

"I don't know!" Hedge snarled. He looked around for his bat, which had rolled into the quarterdeck.

"I'm stupid!" Leo yelled. "Stupid, stupid! I forgot the sonar!"

The ship tilted farther to starboard. Either the monster was trying to give them a hug, or it was about to capsize them. May wasn't very happy with either of the above.

"Sonar?" Hedge demanded. "Pan's pipes, Valdez!"

May was gripping the ropes of one of the sails, and she grunted with the effort of not falling down the deck. "Jason, can't you call some lightning?"

Jason struggled to his feet. "I—" He only managed to shake his head. Summoning the storm earlier had taken too much out of him. He was about as green as the seaweed stuck in the monster's teeth.

"Percy!" Theo said. "Can you talk to that thing? Do you know what it is?"

Even though he was busy wrestling with a stray tentacle-type thing, Percy shook his head, landing a slice with his sword that took down his adversary instantly. "Maybe it's just curious about the ship. Maybe—"

The monster hadn't taken well to Percy's destruction of one of its arms. It lashed the rest of its tendrils across the deck so fast, May didn't even have time to tell him to look out.

One slammed Percy in the chest and sent him crashing down the steps. Another wrapped around May's legs and dragged her toward the rail. Screaming, she latched onto it with all she could, clutching the rigging so tightly her knuckles were aching.

Jason was trying to free her with his sword, but he was still weak. His gold blade cut through the tendrils with no problem, and soon she was stumbling into his arms, both grunting with the impact. May was lucky she hadn't been speared by his sword.

Fighting was getting them absolutely nowhere. Even Frank, who was now trying to gauge out the monster's eyes with his falcon claws, wasn't helping. The monster seemed more annoyed than anything, and it bellowed, still rocking the ship. The mast creaked like it might snap off.

May's eyes landed on a supply crate next to Hazel's feet.

"Leo!" she called, clutching the railing with one hand and gesturing wildly to the crate with her other. "Is that it?"

Leo's gaze followed her until it landed on the box, and he nodded madly, eyes widening. "Hazel! That box! Open it!"

She hesitated. May couldn't blame her; the box's label did read Warning: Do Not Open.

"Open it!" Mayfair and Leo insisted as one.

Leo dashed towards Hazel. "Coach, take the wheel! Turn us toward the monster, or we'll capsize."

Hedge danced through the tentacles with his nimble goat hooves, smashing away with gusto. He bounded toward the helm and took the controls. "Hope you got a plan!" he shouted.

"A bad one." Leo raced toward the mast.

The monster pushed against the Argo II. The deck lurched to forty-five degrees. Despite everyone's efforts, the tentacles were just too numerous to fight. They seemed able to elongate as much as they wanted. Soon they'd have the Argo II completely entangled. Percy hadn't appeared from below. The others were fighting for their lives against nose hair.

Hazel tossed the contents of the box to Leo. He cradled two vials the sizes of an apple, the liquid inside glowing poisonous green.

Mayfair had heard about Greek fire before, but never seen it in action, and just looking at it in glass vials was enough to set off her nerves. Leo had told her the ship was stocked with it in case of emergencies, and that it could wipe out an enemy monster in mere seconds, but she never really thought they'd actually have to use it. She'd heard it could raze entire cities.

But before she could ponder the statistics of how likely Leo was to drop the vials at his feet and destroy the ship whole, he was summoning a white-hot fireball in his hand and burning the tentacle nearest to him. Then, when the blistering heat had the creature open its mouth and bellowing in pain, Leo tossed both the vials of Greek fire deep into its throat.

After that, things got fuzzy. May felt her vision swoop as the ship capsized to the left. She saw a green flash of light inside the pink lampshade of the monster's body. It collapsed back into the water with a ginormous splash, soaking Mayfair straight to the bones.

Then there was silence.

"So, Leo," Theo said, between huffs of air, "do you want to go turn that sonar on now?"