He set the helmet on the seat of the bike and walked back into the halo of the streetlight. “Listen,” he said. “I’m sorry. This is difficult for both of us, but I am telling you the truth: I’m not going to force you to do anything. I still think going to the Saxons is the best plan, but . . .” He palmed the back of his neck. “I haven’t even told them who you are yet. Okay? They still think you’re distant family and that I’m currently retrieving you from a night of clubbing. For now I want you to come with me to Fitz’s, make sure he’s okay, see what he meant about you, and then we’ll talk through the next steps. That’s all.”

His boots echoed on the asphalt as he turned back to the bike. He hadn’t told them? And . . . “Did Mr. Emerson actually say he was in trouble?”

“No. But he’s still not answering his phone, and he left me some strange messages.” Jack’s jaw clenched in the way I was coming to realize meant he was upset. If it really was possible Mr. Emerson was in some kind of danger, that had to take precedence.

“Tell me one thing.” I shifted my weight uncomfortably. “My father. You’re sure you don’t know anything about him?”

Jack hesitated. “I’m not sure of anything.”

He frowned in the direction of the club. I watched him tap his fingers on the motorcycle’s ignition.

Going with Jack was the best of my limited choices. We’d talk to Mr. Emerson. He’d help me get back to Paris to find my mom. And maybe she’d be able to tell me something about my dad.

“I believe you,” I said. “I still don’t trust you, but I believe you. I am only coming with you so we can make sure Mr. Emerson is okay, and so I can talk to him. Just so we’re clear.”

“We’re clear,” he said.

I took the helmet out of his hand, shoved it on my head, and climbed on the back of the motorcycle.

•   •   •

Istanbul at night was all color, like Mr. Emerson had said in his postcard. Bloodred lights along the river to our left, glittering streets rising to our right like the city was climbing a hill. The cold white gleam of a mosque’s dome in the distance, neon storefronts not yet closed for the night.

Straddling the motorcycle in this short, tight dress wasn’t easy, but Jack had shrugged out of his jacket and laid it over my lap. My hips pressed into his, and my arms wrapped around his waist, awkwardly at first, mostly because of the annoyance still lingering between us, but also because I wasn’t used to quite so much Other Person’s Body touching mine. I could feel the muscles in Jack’s chest contract when he turned, and smell his boy smell between his shoulder blades. It made me think back to when he was just a boy I liked. That seemed so far away, and still too close.

Jack swerved around a truck piled high with fruit, and I tightened my grip. I’d imagined riding a motorcycle might be like riding a really fast bike, but it wasn’t. Every time he accelerated, it felt like we might fall off, but I’d dig my fingers in and then we were flying, the rushing air around us dragging against my clothes, my hair, my skin.

We stopped at a light, and the smell of sizzling meat turning on a spit in front of a nearby restaurant wafted past.

“Why do they think union means ‘marriage’?” I said loudly. It was quieter when we weren’t moving, but the helmets muffled our voices. “Could they be wrong?”

“They’re fairly certain about the translation,” he said.

“‘Fairly certain’ is not a good enough reason to ruin someone’s life.” To ruin my life.

Jack turned around, and his helmet smacked mine with a hollow thump.

“Ow. Sorry.” I jerked back and so did he, and I was suddenly even more acutely aware of the ridges of muscle I could feel through his thin cotton T-shirt. I balled my hands into fists, but that was even more awkward, so I let my arms hover, not quite holding on, not quite not.

“Sorry,” he said again. I inclined the ear hole on the helmet to hear him. “I didn’t mean to be insensitive. It’s just that it’s all been abstract before now. In the original Greek of the mandate, the word is gamos. It translates to ‘union’ . . . but it also translates to ‘marriage.’”

Oh.

The light changed and I had to grab on to him again as we took off, flying down a wide street flanked by rows of shops and restaurants. At the next light, people strolled across the street, and I met the eyes of a girl in robes that covered her from head to toe, wrist to ankle, so just her glittering eyes showed. Then I saw the Louis Vuitton bag slung over her shoulder, and I couldn’t help but smile at what to me seemed like a curious contrast but to her was just normal. Even more than Paris, being here felt foreign.

Over the rumble of the bike and the distant low beat of drums and some kind of string instrument, I said, “Where exactly did the Book of Mandates come from?”

Jack leaned back, careful to keep his helmet away from mine. “Oracles were important in Alexander’s time—like, have you heard of the Oracle of Delphi?”

I shifted on the seat, pulling down on my dress. “Yeah.”

“That oracle, others, various seers—they made hundreds of predictions,” he continued. “The ones about the future were collected and became the Book of Mandates.”

I looked out over the river, where two lit boats passed each other, their reflections rippling in the dark water. “What’s the story of this particular mandate?” I said.

The light turned again before he could answer, but after just a few blocks, we got stuck in traffic at a busy intersection. The patio of a nearby bar was filled with well-dressed people laughing and smoking tall hookah pipes, and the sweet scent floated through the night air.

“Before Alexander died, he’d instructed the Diadochi to split his kingdom,” Jack called over his shoulder. I was starting to notice that he slipped into professor-speak when he talked about history, like it took effort for him to talk like a normal seventeen-year-old. “But he surprised them. Instead of declaring that he left it to all twelve of them equally, he said, ‘Krat’eroi.’ In English, that means, ‘To the one who is the strongest.’”

The traffic moved a few feet, and the bike rumbled as Jack inched us forward. He raised his voice to be heard over a portly man in a long robe, selling the mirrored blankets draped over both his arms. “Since then, the Circle has ruled together, as a group of twelve, but the individual families have never stopped trying to determine the one who is the strongest.”