BRIAR FINALLY FELT relaxed as she flew Festus to Chicago.

That was a mistake. All it took was a, "Cyclops!" from Jason and Briar nearly fell off of the dragon. She vowed to herself to never relax in the presence of Leo and Jason.

"Whoa, sleepyhead." Leo said behind Briar. She'd convinced him to teach her how to drive Festus just so he could keep Jason company while he was asleep, and without charmspeak. Gods, she was so good.

"D-Detroit," Jason stammered. "Didn't we crash-land? I thought—"

"It's okay," Leo said. "We got away, but you got a nasty concussion. How you feeling?"

"How did you — the Cyclops—"

"Leo ripped them apart," Briar said. "He was amazing. He can summon fire—"

"It was nothing," Leo said quickly.

Briar laughed. "Shut up, Valdez. I'm going to tell him. Get over it."

"You're driving!" Leo protested.

"Festus is basically doing it all," Briar rolled her eyes. "Let me explain, idiot."

And she did — how Leo single-handedly defeated the Cyclopes family; how they freed Jason, then noticed the Cyclopes starting to re-form; how Leo had replaced the dragon's wiring and gotten them back in the air just as they'd started to hear the Cyclopes roaring for vengeance inside the factory. Briar told him about the other kid the Cyclopes claimed to have eaten, the one in the purple shirt who spoke Latin.

Briar had had time to think about this. A son of Mercury . . . she'd known the kid, but there wasn't a name or a face to put on the kid.

"There are others like us," Jason said.

"Well, obviously," she snorted. "My girlfriend exists. And she definitely has the same tattoo as us, and the purple shirt."

"I — I know . . . but something Hera said. I was having a dream . . ."

He told them what he'd seen, and what the goddess had said inside her cage.

"An exchange?" Briar asked. "What does that mean?"

She could practically feel Jason's frown. "But Hera's gamble is us. Just by sending us to Camp Half-Blood, I have a feeling she broke some kind of rule, something that could blow up in a big way—"

"Or save us," Briar said hopefully. "That bit about the sleeping enemy — that sounds like the lady Leo told us about."

Leo cleared his throat. "About that . . . she kind of appeared to me back in Detroit, in a pool of Porta-Potty sludge."

"Did you say . . . Porta-Potty?" Jason asked.

Leo told them about the big face in the factory yard. "I don't know if she's completely unkillable," he said, "but she cannot be defeated by toilet seats. I can vouch for that. She wanted me to betray you guys, and I was like, 'Pfft, right, I'm gonna listen to a face in the potty sludge.'"

"She's trying to divide us." Briar clutched the reins tighter.

"What's wrong?" Jason asked. Damn it, he knew her too well.

"I just . . . Why are they toying with us? Who is this lady, and how is she connected to Enceladus?"

"Enceladus?" Jason repeated.

"I mean . . ." Shit, shit, shit. Briar hated herself. "That's one of the giants. Just one of the names I could remember."

Leo scratched his head. "Well, I dunno about Enchiladas—"

"Enceladus," Briar corrected. "Though Enchiladas are fun."

"Whatever. But Old Potty Face mentioned another name. Porpoise Fear, or something?"

"Porphyrion?" Briar asked. "He was the giant king, I think."

"I'm going to take a wild guess," Jason said. "In the old stories, Porphyrion kidnapped Hera. That was the first shot in the war between the giants and the gods."

"I think so," Briar agreed. "But those myths are really garbled and conflicted. It's almost like nobody wanted that story to survive. I just remember there was a war, and the giants were almost impossible to kill."

"Heroes and gods had to work together," Jason said. "That's what Hera told me."

"Kind of hard to do," Leo grumbled, "if the gods won't even talk to us."

They flew west, and Briar became lost in her thoughts — all of them bad. She wasn't sure how much time passed before the dragon dove through a break in the clouds, and below them, glittering in the winter sun, was a city at the edge of a massive lake. A crescent of skyscrapers lined the shore. Behind them, stretching out to the western horizon, was a vast grid of snow-covered neighborhoods and roads.

"Chicago," Jason said.

"One problem down," Leo said. "We got here alive. Now, how do we find the storm spirits?"

"How about we follow that one," Jason suggested, "and see where it goes?"

* * *

Briar did not see it, but Jason insisted he did. And right now? He was being hella annoying.

"Speed up!" he urged.

"Do you want to drive this thing?" Briar asked. "Man, Leo, I should've let you drive. Curse my soft heart."

"Your heart is not soft," Leo said, very seriously. Briar scoffed but didn't comment further.

She finally saw the storm spirit dove into the grid of downtown streets. Festus tried to follow, but his wingspan was way too wide. His left wing clipped the edge of a building, slicing off a stone gargoyle before Briar pulled up.

"Get above the buildings," Jason suggested. "We'll track him from there."

"You drive this fucking thing, then," Briar grumbled, but she did what Jason asked.

After a few minutes, Briar spotted the storm spirit again, zipping through the streets with no apparent purpose — blowing over pedestrians, ruffling flags, making cars swerve.

"Oh great," Leo said. "There're two."

He was right. A second ventus blasted around the corner of the Renaissance Hotel and linked up with the first. They wove together in a chaotic dance, shooting to the top of a skyscraper, bending a radio tower, and diving back down toward the street.

"Those guys do not need any more caffeine," Leo said.

"I guess Chicago's a good place to hang out," Briar said. "Nobody's going to question a couple more evil winds."

"More than a couple," Jason said. "Look."

The dragon circled over a wide avenue next to a lake-side park. Storm spirits were converging — at least a dozen of them, whirling around a big public art installation.

"Which one do you think is Dylan?" Leo asked. "I wanna throw something at him."

Briar snickered, but then she noticed something else. On the art installation, she saw the image on the screens change to a woman's face with her eyes closed. Her smile faded.

"Leo . . ." Jason said nervously.

"I see her," Leo said. "I don't like her, but I see her."

Then the screens went dark. The venti swirled together into a single funnel cloud and skittered across the fountain, kicking up a waterspout almost as high as the monoliths. They got to its center, popped off a drain cover, and disappeared underground.

"Did they just go down a drain?" Briar asked. "How are we supposed to follow them?"

"Maybe we shouldn't," Leo said. "That fountain thing is giving me seriously bad vibes. And aren't we supposed to, like, beware the earth?"

"Put us down in that park," Jason suggested. "We'll check it out on foot."

Festus landed in an open area between the lake and the skyline. The signs said Grant Park, and Briar imagined it would've been a nice place in the summer; but now it was a field of ice, snow, and salted walkways. The dragon's hot metal feet hissed as they touched down. Festus flapped his wings unhappily and shot fire into the sky, but there was no one around to notice. The wind coming off the lake was bitter cold. Anyone with sense would be inside. Briar's eyes stung so badly, she could barely see.

They dismounted, and Festus the dragon stomped his feet. One of his ruby eyes flickered, so it looked like he was blinking.

"Is that normal?" Jason asked.

Leo pulled a rubber mallet from his tool bag. He whacked the dragon's bad eye, and the light went back to normal. "Yes," Leo said. "Festus can't hang around here, though, in the middle of the park. They'll arrest him for loitering. Maybe if I had a dog whistle . . ."

He rummaged in his tool belt, but came up with nothing.

"Too specialized?" he guessed. "Okay, give me a safety whistle. They got that in lots of machine shops."

This time, Leo pulled out a big plastic orange whistle. "Coach Hedge would be jealous! Okay, Festus, listen." Leo blew the whistle. The shrill sound probably rolled all the way across Lake Michigan. "You hear that, come find me, okay? Until then, you fly wherever you want. Just try not to barbecue any pedestrians."

The dragon snorted — hopefully in agreement. Then he spread his wings and launched into the air.

Briar took one step and pain shot up her leg. "Fuck!"

"Your ankle?" Jason frowned. "That nectar we gave you might be wearing off."

"It's fine." She shivered. She took a few more steps with only a slight limp, but she was trying to not show any signs of weakness. She hated being seen hurt like this. And she hated her stupid ankle.

"Let's get out of the wind," he suggested.

"Down a drain?" Briar shuddered. "Sounds cozy."

They wrapped themselves up as best they could and headed toward the fountain.