They were crossing the Potomac when Sasha spotted the helicopter. It was a sleek, black military model just like the one they'd seen at Westover Hall. And it was coming straight toward them.

"They know the van," Percy said. "We have to ditch it."

Zoë swerved into the fast lane. The helicopter was gaining.

"Maybe the military will shoot it down," Grover said hopefully.

"The military probably thinks it's one of theirs," Percy said. "How can the General use mortals, anyway?"

"Mercenaries," Zoë said bitterly. "It is distasteful, but many mortals will fight for any cause as long as they are paid."

"But don't these mortals see who they're working for?" Percy asked. "Don't they notice all the monsters around them?"

Zoë shook her head. "I do not know how much they see through the Mist. I doubt it would matter to them if they knew the truth. Sometimes mortals can be more horrible than monsters."

The helicopter kept coming, making a lot better time than they were through D.C. traffic.

Thalia closed her eyes and prayed hard. "Hey, Dad. A lightning bolt would be nice about now. Please?"

But the sky stayed gray and snowy. No sign of a helpful thunderstorm.

"There!" Bianca said. "That parking lot!"

"We'll be trapped," Zoë said.

"Trust me," Bianca said.

Zoë shot across two lanes of traffic and into a mall parking lot on the south bank of the river. They left the van and followed Bianca down some steps.

"Subway entrance," Bianca said. "Let's go south. Alexandria."

"Anything," Thalia agreed.

They bought tickets and got through the turnstiles, looking behind them for any signs of pursuit. A few minutes later, they were safely aboard a southbound train, riding away from D.C. As the train came above ground, they could see the helicopter circling the parking lot, but it didn't come after us.

Grover let out a sigh. "Nice job, Bianca, thinking of the subway."

Bianca looked pleased. "Yeah, well. I saw that station when Nico and I came through last summer. I remember being really surprised to see it, because it wasn't here when we used to live in D.C."

Grover frowned. "New? But that station looked really old."

"I guess," Bianca said. "But trust me, when we lived here as little kids, there was no subway."

Thalia sat forward. "Wait a minute. No subway at all?"

Bianca nodded.

"Bianca," Zoë said. "How long ago..." Her voice faltered. The sound of the helicopter was getting louder again.

"We need to change trains," Sasha said. "Next station."

Over the next half hour, all they thought about was getting away safely. They changed trains twice. Bianca had no idea where they were going, but after a while they lost the helicopter.

Unfortunately, when they finally got off the train they found themselves at the end of the line, in an industrial area with nothing but warehouses and railway tracks. And snow. Lots of snow. It seemed much colder here.

They wandered through the railway yard, thinking there might be another passenger train somewhere, but there were just rows and rows of freight cars, most of which were covered in snow, like they hadn't moved in years.

A homeless guy was standing at a trash-can fire. They must've looked pretty pathetic, because he gave them a toothless grin and said, "Y'all need to get warmed up? Come on over!'

We huddled around his fire, Thalia's teeth were chattering. She said, "Well this is g-g-g-great."

"My hooves are frozen," Grover complained.

"Feet," Percy corrected, for the sake of the homeless guy.

Sasha pulled on her gloves and tugged her hat down so that it almost was at her eyes. Her jacket was zipped to the very top of the collar.

"Maybe we should contact camp," Bianca said. "Chiron—"

"No," Sasha said. "They can't help us anymore. We gotta finish this quest ourselves. Maybe Mom can help, since I'm here and Percy and you, Bianca, but I doubt it."

Percy gazed miserably around the rail yard.

"You know," the homeless man said, "you're never completely without friends." His face was grimy and his beard tangled, but his expression seemed kindly. "You kids need a train going west?"

"Yes, sir," Percy said. "You know of any?"

He pointed one greasy hand.

Suddenly Bianca noticed a freight train, gleaming and free of snow. It was one of those automobile-carrier trains, with steel mesh curtains and a triple-deck of cars inside. The side of the freight train said SUN WEST LINE.

"That's... convenient," Thalia said. "Thanks, uh..."

She turned to the homeless guy, but he was gone. The trash can in front of them was cold and empty, as if he'd taken the flames with him.

⚰️💀

And Apollo strikes again.