Unlike Caitlin, Petula knew about Val, because she was the one who had been impersonating Nick online. She’d been doing it for quite some time now. At first it was just for entertainment value, but more recently it had a purpose.

She had created a profile for him in a medieval weaponry chat room, and had struck up a conversation with the most intimidating girl she could find, for the purpose of blindsiding Nick exactly as she had done today.

It wasn’t hard, really. Her own knowledge of Dark Age death devices had captured Val like a heretic in an iron maiden. And so, while Nick floundered at his door, negotiating with an armed teenage huntress, Petula was on the move, waiting for Ms. Planck at the harpist’s house.

She had already ignored three phone calls from Mitch. She knew why he was calling, and she listened to his messages only because his increasingly frantic voice soothed her.

“This will be a feather in your cap, Petula,” Ms. Planck said as she arrived. “If we retrieve this item because of you, the Accelerati won’t forget it. You’ll be well on your way up the secret society’s ladder, and they will give you the respect that you deserve.” Then she added, “And it won’t look bad for me either—I need something more to show for my efforts. Do you know how close I was to getting a list of the missing objects from Nick? That would have made me the belle of the Accelerati ball!”

“The Accelerati have a ball?”

“Honestly, Petula!” Ms. Planck said, shaking her head. “That’s a figure of speech.” Then she suggested, “Perhaps you could sweet-talk that list out of him.”

Petula knew that was as unlikely as pigs flying. Although, considering some of the experiments she’d heard about in the Accelerati’s genetic research department, flying pigs were not entirely out of the question.

They arrived at the harpist’s home, which was unremarkable—just one on a street of similar ranch houses. Petula reached out to ring the bell, but the door opened before she could.

The woman inside seemed to be in her thirties. She was wearing a loose-fitting flowery dress, and she had the air of contentment usually reserved for people too stupid to know that their lives were miserable.

“Hello,” she said, in a rather musical tone. “You’ve come for the harp, haven’t you? I was expecting two young men, but things change, I suppose.” The smile never left her face. It was calming in a disturbing sort of way. The woman exuded a sense of inner peace and trust that made Petula not want to trust her at all.

“Come in,” she said. “Stay for a moment, won’t you? There’s no need to rush.”

Ms. Planck, however, got down to business the moment they stepped inside. “The harp is part of a collection that should not have been split up. I hope you can understand our need to retrieve it.”

“Yes, of course.”

“We’ll buy it back,” Petula said, wedging herself into the negotiation.

“And for much more than you paid for it,” Ms. Planck added.

The woman just looked at the two of them, her eyes smiling as broadly as her lips, it seemed. “Oh, you don’t have to pay me. Take it as my gift. I’ve come to realize I can’t keep it. Now that it’s touched my life, I’m happy to let it move on.”

This made Petula even more suspicious—and probably Ms. Planck, too, because she, more than anyone, knew that there was no such thing as a free lunch.

“So then what do you want?” Petula asked. “You must want something.”

Ms. Planck gently touched Petula’s arm to quiet her, and said, “Can you show it to us?”

The woman led them into a den. There it sat beside a baby grand piano. It was about four feet high and was gunmetal gray with gold highlights. A beautiful object, with one very obvious problem.

“It really doesn’t have strings,” said Petula.

The woman chuckled lightly. “Oh, it most certainly does.” Then she asked, “Would you like to hear me play?”

Petula couldn’t imagine how a person could play a stringless harp, but Ms. Planck said, “Yes, we’d love to hear it, if you would be so kind.”

The woman pulled up a small stool, tilted the harp so that it rested on her shoulder, and began to move her fingers in the empty space where the strings should have been.

Petula heard nothing. Nothing at all. But she could feel the music. It seemed to echo inside her. Not just in her bones, but in a deeper place she never knew existed—or at least had never accessed. The soundless music tapped the well of her soul.

“My God,” whispered Ms. Planck. “It’s strung with cosmic string!”

Petula had heard of cosmic string theory. How the universe was made up of invisible threads stretching beyond the three dimensions that humans can experience. No wonder this woman seemed to be tuned in to something larger than herself. Because she was! She was playing the universe!

Then the howling began. Just as the man at the Beef-O-Rama had told them, this delicate melody, out of the range of human hearing, was calling to dogs like an ultrasonic whistle. And they sang with it, harmonizing. Like the man said, it wasn’t music, but whatever it was, Petula wanted it to last.

But Ms. Planck said, “Thank you. It’s lovely, but we really need to go.”

The woman looked up—not at Ms. Planck, but at Petula, who had crossed the room and was now standing just a few feet away from the harp. The soundless music had drawn her. She felt betrayed by her own legs, and would have to find a way to punish them later.

“You want to play it, don’t you?” the woman said kindly. “I think you should.”

“No!” said Ms. Planck, and she pulled Petula back, whispering into her ear. “Cosmic strings are capricious and unpredictable. You don’t want to touch them.”

“But…but just a single strum couldn’t hurt.”

“Of course it could! Look at her.” They both turned to the smiling woman, whose eyes seemed to be seeing through them to another place entirely. “Clearly she’s lost her mind!”

Then Ms. Planck addressed the woman. “We really do need to go. Petula, grab the light end, and be careful not to touch the strings. I’ll take the base.”

The woman stepped back and let them lift the harp. They moved it to the doorway, where Ms. Planck put down her end. “Wait here,” she told Petula, then went back to the woman.

“I can’t just take the harp without leaving you something.”

The woman heaved a sigh that seemed both blissful and melancholy. “Yes, I know,” she said.

“It’s not what you want, but it’s necessary.”

“Yes, I know,” she said again.

Petula was much more interested in the harp than the transaction. Even silent, the invisible strings seemed to resonate. So Petula reached out a single finger, moved it toward the seemingly empty space, and as soon as she felt the tiniest bit of resistance, she plucked the unseen string.

The effect was immediate. It was intense, and too much to process all at once. If that’s what a single string did, Petula couldn’t imagine what playing all of them would do—especially if you knew how to play.

Ms. Planck must have felt the vibration, because she snapped her eyes back to Petula. “I told you not to!”

“I didn’t mean to! My hand slipped!”

“It spoke to you!” the woman said, overjoyed by the prospect. “What did it tell you? What did it say?”

Petula just shook her head.

“Enough!” said Ms. Planck. “Thank you for your assistance, but we’re done here.” Then she pulled something out of her pocket. It wasn’t money, but a small silver ball about the size of a cherry. She dropped the silver marble at the woman’s feet and took several steps back. Suddenly things began to change. The colors in the den started to fade. Piano strings broke with harsh twangs.

Ms. Planck returned to the harp and lifted the heavy end. “Time to go,” she said.

Petula couldn’t help looking back. What she saw would have made a lesser person scream. The woman’s skin was puckering. Her clothes began to tatter. Still she smiled. Still she held Petula’s gaze.

“What was that?” Petula asked Ms. Planck. “What did you do?”

“It’s called a temporal accelerator. You might call it a time bomb.”

Now Petula understood. Everything within a field of about ten feet around the woman was aging at incredible speed—including the woman herself. In the blink of an eye, she looked fifty. Sixty. Eighty. Her hair grayed, her skin wrinkled, and her body withered before Petula’s eyes.

“Don’t worry, dear,” she croaked from within the time field, in the voice of a very old woman. “I am complete…and all is as it should be…”

Then her smile became the fleshless grin of a skeleton. Her bones crashed to the ground and disintegrated. The piano collapsed, and when the field faded, all that remained of the den was a rusty piano soundboard on a dusty, crumbling floor. The entire room had been consumed by time.

“We do the things we must do,” Ms. Planck said. “Don’t think too long on it, Petula.”

And so, Petula resolved she wouldn’t, not if she wanted to be a full-fledged member of the Accelerati. Even though she had just seen a woman disintegrate before her eyes, she couldn’t let emotions or regrets get in the way. They had come here for the harp; they got the harp, end of story.

Except that the dead woman was right. The harp had spoken to her. Not in words, but in the silky vibration of feelings. Of intuition. Only now was Petula able to put that feeling into five simple words:

“You must complete the circuit.”