“Okay, Dad.” Eureka let the walls embrace her.

The temperature dropped. The ceiling did, too. Lit candles flickered sporadically along the way. Their shallow light faded into long stretches of darkness before the next candle appeared. Eureka sensed her loved ones at her back. She had no idea what she was leading them toward.

Distant sounds echoed off the walls. Eureka stopped to listen. She could only hear them in her good ear, which she realized meant the voices were of her world, not Atlantis. They grew louder, closer.

Eureka widened her stance to shield the twins. She held the torch with both hands like a bludgeon. She would strike whatever came.

She cried out and swung the torch—

At the edge of its light stood a small, dark-haired, barefoot child. He wore nothing but a pair of ragged brown shorts. His hands and face were grimy with something black and glossy.

He called to them in what could have been Turkish, but Eureka wasn’t sure. His words sounded like the language of a nearby planet from a thousand years ago.

Slowly, William stepped out from behind Eureka’s leg. He waved at the little boy. They were the same age, the same height.

The boy grinned. His teeth were small and white.

Eureka relaxed for half a second—and that was when the boy lurched forward, grabbed William’s and Claire’s hands, and dragged them into the darkness.

Eureka screamed and ran after them. She didn’t realize she had dropped the torch until she’d run deep into blackness. She followed the sounds of her siblings’ cries until somehow her fingers found the waist of the boy’s shorts. She jerked him to the ground. Cat held the torch to light Eureka’s struggle with the boy.

He was shockingly strong. She strained fiercely to pry the twins from his grip.

“Let go!” she shouted, not believing that anyone so small and young could be so strong.

Ander heaved the boy into the air, but the child wouldn’t let go of the twins—he lifted them off the ground with him. William and Claire writhed and cried. Eureka wanted to dismember the boy and make his head part of the mosaic on the walls.

Neither she nor Ander could pry the boy’s tiny fingers free. Claire’s arm was swollen and red. The boy had worked himself out of Ander’s hold, had slipped through Eureka’s exhausted hands. He was dragging the twins away.

“Stop!” Eureka shouted, despite the absurd futility of the word. She had to do something. She scrambled after the three of them and, without knowing why, she began to sing:

“To know, know, know him is to love, love, love him.”

It was a Teddy Bears song from the fifties. Diana had taught it to her, dancing on a humid porch in New Iberia.

The boy stopped, turned around, and stared at Eureka. He gaped like he’d never heard music before. By the end of the chorus, his iron grip had relaxed, and the twins slid away.

Eureka didn’t know what to do but keep singing. She had reached the song’s eerie bridge, with its one sharp note beyond her range. Cat joined in, nervously harmonizing; then her father’s rich, deep voice met Eureka’s, too.

The boy sat cross-legged before them, smiling dreamily. When he was sure the song was over, he rose to his feet, looked at Eureka, and disappeared into the recesses of the cave.

Eureka collapsed on the ground and pulled the twins to her. She closed her eyes, enjoying the fall of their breath against her chest.

“I take it that wasn’t Solon,” Dad said from his bower, and everyone managed to laugh.

“How did you do that?” Ander asked.

Eureka recognized the wonder in his eyes from a look that Diana had given her a few times. It was a look only someone who knew you really well could give, and only when they found themselves amazed to still be surprised by you.

Eureka wasn’t sure how she had done what she’d done. “I used to sing that when the twins were babies,” she said. “I don’t know why it worked.” She stared in the direction the boy had run. Her pulse raced from the victory, from the surprising, simple joy of singing.

It was the first time she’d sung since Diana died. She used to sing all the time, even make up her own songs. Back in seventh grade, when they’d still been friends, Maya Cayce had entered a school poetry contest using song lyrics lifted from Eureka’s journal. When Eureka’s stolen song won, neither girl mentioned it. Maya won twenty-five dollars, had her poem read over the intercom on Friday morning. It became the thing between them, a loaded glance over sleeping-bagged knees at slumber parties, and later, over kegs at house parties. Was Maya dead now? Had Eureka taken her life the way she’d taken Eureka’s words?

“I think that boy wanted us for his friends,” William said.

“I think we have our first fan.” Cat handed the torch back to Eureka. “Now we need a band name. And a drummer.” Cat brainstormed band names as they continued more cautiously down the narrow passage. Her rambling was comforting, even if Eureka couldn’t afford the energy to attend to every manic idea darting catlike through her friend’s mind.

White and dark blue tiles now paved the floor beneath their feet. Mounted on the wall was a marble plaque, into which were chiseled the words Memento mori.

“Thanks for the reminder,” Cat quipped, and Eureka loved that Cat knew the sign meant “Remember that you must die” even though she hadn’t been in the Latin class where Eureka had learned the phrase the year before.

“What does it mean?” William asked.

“A slave called it out to a Roman general who was going into battle,” Eureka said, hearing her Latin teacher Mr. Piscadia’s drawl in her mind. She wondered how he and his family had weathered her flood. Once she’d seen him and his son at a park walking a pair of brindle boxers. In her imagination, a giant wave washed away the memory. “It meant ‘You are mighty today, but you’re just a man, and you will fall.’ When we studied it in Latin class, everyone got hung up on how it was about vanity and pride.” Eureka sighed. “I remember thinking the words were comforting. Like, someday, all this will end.”