“My God,” he said, with a hint of delight. “How did you know to do this?”

With as little explanation as possible, she told him about the secret messages her mother had hidden in her violin case, and in her suitcase when she traveled.

“She wanted you to be able to read it,” he said, practically glowing with excitement. “She thought that someday you might have to find the astrolabe. Do you understand any of the clues?”

Etta shook her head, scanning the words over and over again, wondering if she’d been wrong—if it was meant to be another shape. The words didn’t make any sense.

“If we assume this is a list of instructions, directions, then I believe we can ignore the first clue,” Nicholas said, taking the letter from her. “The second, Tell tyrants, to you, their allegiance they owe, refers to the place where Nathan Hale was killed—the passage we came through—meaning the next one is likely relevant to us now: Seek out the unknown gods whose ears were deaf to lecture. Does that stir anything in your memory?”

Helplessness tugged at her as she shook her head, and she felt her hope start to fray. How were they going to figure out multiple clues like this in seven days?

“What do ‘unknown gods’ have to do with London during the Second World War? Are they people? A certain faith? The last clue tied the location of the passage to one man’s death.” And the clue had used a song that her great-grandfather was fond of belting out now and then. Would this one relate to her family in a similar way—be as personal?

Something nagged at her as she thought back to the Dove, the Artillery Park, but she brushed it aside as Nicholas said, “Lecture…lecture, lecture, lecture…”

He spun toward her so quickly, he almost knocked her back a step. His eyes lit up, making the planes of his face seem almost boyish. “Is it possible it’s referring to St. Paul’s Areopagus sermon?”

Etta returned his eager expression with a blank one.

“Heathen!” Nicholas teased. “Acts 17:16–34. The Apostle Paul gave a sermon—a lecture, in fact, as it was against Greek law to preach about a foreign deity—in Athens, at the Areopagus.”

“I’ll take your word for it.”

He chuckled, absently brushing a featherlight finger along her chin. He didn’t seem to realize he’d done it, but every inch of Etta’s skin was sparking with awareness.

“The Areopagus is the rocky area below the Acropolis. It served as the city’s high court of appeals in ancient times,” he explained, and Etta felt both impressed at his knowledge and terribly inadequate in the face of it. “I’ve read of it. Captain Hall saw himself as a philosopher as much as a seaman—he was educated at Harvard, if you can believe it—and kept any number of treatises around in the hope that Chase or I would stumble upon them one day. And Mrs. Hall was rather stringent in our biblical education.”

“I wish I could say the same,” Etta muttered. The only service she’d attended inside of a church had been the funeral of Oskar, Alice’s husband. Considering the role of religion in the eighteenth century, the depth of Nicholas’s knowledge shouldn’t have surprised her. She found herself leaning toward him, something sparking and warming at the center of her chest as she reappraised him in light of this. For the first time, Etta was truly grateful he had followed her through the passage.

“The sermon is something to the effect of, ‘Ye men of Athens, I perceive that in all things ye are too superstitious. For as I passed by, and beheld your devotions, I found an altar with this inscription: To the Unknown God.’ The sermon was centered on his distress at seeing the Athenians worshiping false idols—the Greek pantheon of gods.”

“And the connection between London and Ancient Greece is…?” Etta prompted, hoping he’d have the answer, since she didn’t.

“Architecture, law, statues, and art,” he offered. “I’d imagine that it’s a place or thing you have a personal connection with. Have you visited this city before?”

Etta nodded. Any number of times. She, her mom, and Alice had flown back to visit, spent summers in rented flats to escape the sweltering heat of New York. Alice had grown up in London, and…well, she’d always been told her mother had as well, though that seemed up for debate now. The truth and fiction in her stories had started to bleed together, damaging them, like a waterlogged painting.

During their holidays, they’d rented any number of flats, but remembering them now, none of them stood out from the others. They’d walked all over the city, visiting the parks, the house Alice had grown up in—they’d gone to the theater, museums—

“Oh!” she said. It felt like the thought reached up and slapped her in the face. She turned to Nicholas, almost giddy that she could finally explain something he might not know. “This idea is crazy, but…London—the British Museum—has a ton of artifacts from ancient Greece, doesn’t it? The most famous set were removed—or looted, depending on who you’re talking to—from the Parthenon by a British lord, Elgin, who brought them back here and sold them to the British government for the museum. It’s a whole legal mess.”

Etta rocked back onto her heels, looking up at the clouds and smoke trailing overhead. “I might be reaching here, but the Acropolis, and the Parthenon, are so close to the Areopagus, it feels like they’re linked. It’s been a while since I visited that room of the museum, and I can’t exactly remember what the Elgin Marbles depict—some kind of battle, I think. But there are statues of men and women…”