It happened in an instant.

For one second she could only see the blackness stretching down past the floor, and wondered whether or not she was going to get E-Z Death. And in the next second there was a light, coming right at her as she fell. Just when she thought it was going to stop, it slammed into her, stealing the breath from her lungs. It swung her up, past the breach in the ceiling. That was impossible… it must have been a trick. Her gray eyes fluttered shut and she imagined the talking-to she would give Hades when this was all over. When they were open again she saw the lights of New York City twinkling like fireflies.

And a girl standing over her, knife in hand. Gods dam it, Annabeth thought. There was no way she had gone through everything she had over the past five years to nearly die on a minor quest before getting mugged and stabbed by some prosti-

"Hey there," the girl wiggled her long fingers. "I see you fell in a hole."

Annabeth groaned, sitting up. She was sprawled on the roof of the same building she had fallen into, a few feet from the gaping hole. She scooted farther away from it. The girl before her was probably around her age, but she looked like a woman. She was tall, and loftily built, curved in all the right places, her dark hair hanging to her waist. She could've fit in with the Aphrodite cabin without a second thought.

But no—only a few Aphrodites had black tattoos curling up their arms and collarbones, and none looked like this. And Aphrodites rarely held knives like that. This girl held the glowing, white dagger in her hand with a trained arm, her fingers wrapped skillfully around the hilt. She knew how to use that weapon, and many more too—and she wasn't afraid of doing so, either.

"Can you talk—does she talk?" Her first statement was directed at Annabeth, but then she turned her head to speak to someone next to her.

"Too much," the person replied. "And she's very bossy."

Annabeth narrowed her eyes at Rachel. The girl shrugged unapologetically.

"That's fine," said another girl. "You can always outrun the people you don't like and use them as bait."

Annabeth turned and narrowed her eyes at… Rachel.

She blinked, looking back and forth between the two. Not Rachel?

"I know," said the tall girl in the center, reading her thoughts. "Freaky, right?"

Upon second inspection, Annabeth noticed that there were not, in fact, two Rachels (thank the gods), but rather Rachel, and a girl who looked quite like her. She had the same red hair, big, green eyes, and petite frame; but there were differences. The other girl looked older, maybe by a year or two, and had a good deal of muscle packed around her small figure. She also had the strange tattoos etched into her pale skin.

"I'm just kidding," said the girl, extending her hand. "My name's Clary. Hope you don't hate me."

Annabeth didn't have a reply to that just yet. She shook Clary's hand anyway. Despite her carefree tone, her eyebrows were drawn with skepticism. She too had a glowing dagger in her hand. What were they made of? They were translucent, but not made of glass, and they radiated a strange sort of shimmering light. The edge looked deadly sharp, and she was sure this girl knew how to use it.

The black-haired girl offered her hand likewise. "Isabelle. But you can call me 'Your Savior.'"

The daughter of Athena accepted her hand, mulling over the past few moments.

"You saved me?" She asked.

"That's what 'Your Savior' means."

"How? Where were you?"

Isabelle crawled to the edge of the hole. She looked around for a moment, and then pointed inside, grinning.

Annabeth shook her head. "Why would you be in there? This building is too unstable to enter safely."

The girl tucked away her knife, the light snuffed out in layers of black clothing. "The same reason you were on the roof." She walked a few steps, as if the hotel wasn't collapsing beneath her. "And who said anything about 'safely'?"

With that, she yanked the smaller girl—Clary— to her feet. "Let's go, Fray. Business to handle and whatnot."

"I guess we're pretty lucky you were here," Annabeth said. "Which raises the question: why didn't you help us before I started falling to my death?"

Isabelle turned, rolling her eyes. "Well, Miss Sassypants, not every rescue mission happens that quickly. We had to set up the rope, and in a building this old, that is a difficult thing to do. You know, safely."

Now Annabeth rolled her eyes. "Thanks for that."

"Anytime," the girl called from the other side of the roof. "And try not to find yourself on a dilapidated rooftop again, as that can be a very dangerous highway to death."

"I've been on a highway to death," she muttered. "And it sure as Hades doesn't look like an old hotel."

Rachel poked her shoulder and raised her brow. She shook it off. Isabelle gestured for her companion to leave with her.

"Should we really be leaving them alone?" Clary inquired. "This is not the safest place to be hanging out around."

Isabelle squeezed the hilt of the dagger protruding from her belt. "Well…"

Clary turned to the two campers. "Why were the two of you up here?" Her voice had hardened.

Annabeth looked to Rachel and Rachel looked to Annabeth. "We were chasing something."

"What were you chasing?"

"It was… more or less a…"

In that moment, a creature dragged itself onto the roof from within the hole, lugging a bronze leg behind it. It stood and faced the girls, baring its scarlet fangs.

"That," Rachel finished.

It charged. Annabeth ducked, drawing her bronze dagger. The empousa spun around her and snapped at her neck. The girl, still facing the other way, swept out her arm and brought the weapon down onto its neck. It hit home, passing through its esophagus, the tip protruding wretchedly from its throat. The wound bubbled with crimson blood and the creature coughed, more blood squalling from its mouth. Annabeth turned and loosened her dagger, wiping it on her T-shirt.

"That was quick."

At that moment, another pale-faced creature erupted from the hole. This one, to Annabeth's surprise, lacked the trademark, mismatched legs and feminine appearance of an average empousa. It glared at the group of warriors on the rooftop before grinning, revealing needle-sharp fangs. "I see the Nephilim have found friends," he purred. "Interesting. I thought I smelled blood on the roof."

He pointed to the pile of ash at their feet that was once the empousa. "A fallen comrade?" He asked. Then his nostrils flared. "No. Not of mine."

He took a step closer. Isabelle drew her knife. "You're not comrades with anybody."

"No," he said surprised, as if just recalling this fact. "No, not at all. But I did not mention it being my fallen comrade. Did I?"

"We don't keep vampires as—" Isabelle stopped short. The rooftop became still. And silent. The only movement was her long hair fluttering in the wind.

Vampires? Annabeth wondered. She supposed that was the name mortals gave to the empousai they found. But was this an empousa? And were these mortals? She doubted both.

"Really?" Asked the… empousa, surprised. "You do not keep vampires as—what? Comrades? Pets? Because you certainly seem attached to that traitorous Daylighter-"

"Sammael!"

There was a movement and a streak of light out of the corner of Annabeth's eye and the empousa fell, scarlet blood flooding from his heart before he crumbled to ashes, joining the heap already on the ground. Annabeth turned to find Clary with her arm poised in a throwing position. She brushed off her palms and retrieved her glowing knife. Her lips were pressed firmly together; she was pissed.

Isabelle said, "We weren't supposed to-"

"I know," was the girl's reply. She sheathed her dagger and faced the other way. Definitely pissed.

"Interesting," noted Annabeth.

Isabelle and Clary, as if remembering their company, exchanged a glance. "I don't suppose you… know what a Shadowhunter is?"

The demigod shook her head. The Oracle shook hers.

"Where'd you learn to fight?" Isabelle inquired.

"Where did you?"

Rachel peered at the strange girls. "I think we can all agree that that was not an empousa, and that what you did is not something mortals do," she said. "So say it loud, say it proud, you're… Nephilim?" She looked to the daughter of Athena. "Do you have any clue what that is?"

Annabeth shook her head. "But they do."