“I’m not mathematical, sir,” she admitted. Languages, history, and literature: those all made more sense to her than this confusing tangle of numbers and symbols. “A great deal of this is calculations and plans that mean nothing to me.”

“I’m more curious if there’s anything useful in there. Names?”

“Not a one, I’m afraid. He’s very cagey about the people he’s working with.”

Mr. Ferreira sighed heavily and sat back in the chair, crossing his legs and lacing his fingers over his knee. “Then we’re wasting your time.”

“Not at all,” she said. “I’ve noted, for example, he doesn’t mention the victims in his calculations. Or the table on which the spell was inscribed. Those had to have been added later in the process.”

“That would throw off all his calculations,” Mr. Ferreira said. “For buoyancy and weight, I mean.”

She nodded. “Also, the houses aren’t wood, as everyone thinks. The wood is a veneer, over cork. That’s what actually makes them float. If the chain broke on any one of them, it would probably pop to the surface like a rubber ball.”

He shrugged. “I was told those charms on the top were useless.”

She told him then what she’d read about the patron who’d made it all possible, but didn’t have a name for the man, which made the information useless. “I’ll read more this afternoon, sir. Perhaps he’ll say who’s paying for his creation.”

He nodded, his lips pursed, and then cautiously asked, “Does the name Maria Melo mean anything to you?”

It was a common name, but Oriana didn’t actually know anyone who bore it. “No, sir.”

“Have you ever been to a tavern called The White Rose?” he asked then.

That tavern was frequented by servants from up and down the Street of Flowers. Carlos had once suggested she meet him there, although at the time she’d thought it a joke. And it was one of Heriberto’s favored haunts. When her master wasn’t on his boat, he could often be found there. “I’ve never been inside,” she said. “Can I assume that Mrs. Melo has?”

He looked grim. “My cousin talked to the Amaral servants yesterday. Both the first footman and the lady’s maid said they met her there. They said she asked after you. How you were faring, how you liked the household. The maid thought Mrs. Melo was your cousin. Do you have any cousins here?”

Oriana laid one mitt-covered hand over her mouth. How should she answer that? He’d met Nela and so must suspect about the exiles, so it was a logical question, but her father was her only direct kin. No, the woman had to be lying. And given it was a tavern Heriberto frequented, he had to figure into this somehow. Oriana dropped her hand back to her lap. “She’s your saboteur, isn’t she?”

“We don’t know that,” he said swiftly, as if to reassure her again. “But if she is, then she had to know you’re not human.”

“You knew,” she pointed out, and then felt guilty for withholding information he might need. “My master frequents that tavern, as well. It’s possible he gave her that information, although I can’t think why he would.”

Mr. Ferreira pinched the bridge of his nose. “Would your master willingly put you in that position? In the floating house?”

Oriana thought of her father speaking of paying Heriberto more money. If Heriberto was willing to stoop to extortion, what else might he be willing to do? “He might,” she admitted. “I’m not one of his favorites.”

“And you lived in one of the houses in question,” Mr. Ferreira said. “Are there other spies like you in comparable positions? Or some of your people who chose to live here? I don’t need specifics—just a general idea whether you were one of a hundred or the only choice.”

Oriana knew of six other spies currently in the city, none of whom worked on the street of the aristocrats. Of the exiles, the only one she knew who frequented the street was her own father. He visited the Pereira de Santos mansion often, but that house had already appeared in the water, so he’d been bypassed. He didn’t actually live in that house anyway. “I may have been the only choice,” she whispered, a sick feeling swelling in her stomach.

Mr. Ferreira pushed himself out of his chair and came to loom over her. He set a hand lightly on her shoulder. “I meant what I said last night, Miss Paredes.”

She looked up at him. No, he hadn’t forgotten last night’s extraordinary discussion either. She could see it in his eyes, an awareness of her as more than a servant. He looked at her like she was a woman, perhaps even a lover. But opening that door would only lead her to pain. She wasn’t the sort who could take a lover and then go on her way. She just . . . wasn’t. Her scruples wouldn’t allow it. Even for a male as fascinating as Duilio Ferreira. It would break her heart, and she refused to do that to herself. She nodded jerkily. “I know, sir.”

His lips pressed together, possibly in vexation. She wasn’t quite certain how to read that expression. Then he stepped back and left without another word.

As the tram drew closer to Matosinhos, Duilio could see the port of Leixões to the north. The port was an unfinished work that must either be considered art or an eyesore, progress brought to a standstill. The builders had begun constructing two stone “arms” intended to stretch out into the sea to act as breakwaters to protect the ships that would someday sail up the Leça River into the port. Silhouetted against the horizon, two Titans of iron and steel waited—giant steam-powered cranes that ran on rails to the ends of those breakwaters. One sat on each abandoned arm, capable of going back to work and moving giant blocks of stone . . . as soon as the prince should deign to give his permission. Duilio doubted that would happen while this prince was alive.

Not for the first time, Duilio wondered if it wouldn’t be better for Northern Portugal if the seers were correct and the prince was doomed to die. Somehow Miss Paredes had changed the odds of that prophecy coming true. Not through her own choices, of course. She’d been forced into that position. He hated the price at which that had come. He sighed and returned to surveying the passengers of the tram.

The man in the dark suit was the one who concerned him. When he’d gotten on the tram at Massarelos, a prickle had gone down Duilio’s spine. He’d settled a couple of seats behind Duilio and pulled a folded newspaper from under his arm. He didn’t appear to be an immediate danger, but Duilio felt sure the man had no other business there other than to watch him.

Duilio dug into a pocket for his watch, flicked the lid open, and held the case to one side, trying to get a glance at the man’s face in the mirror secreted inside the lid. He didn’t look familiar. In his midthirties, dark-haired, and average in size, he wouldn’t stand out in a crowd. Duilio studied him a moment longer while the man perused a copy of the Gazette. He closed the case then and slid the watch back into his pocket.

While at the house Duilio had changed into a more casual suit—one that Marcellin found plebian. But it would be better for running should he find that necessary. He’d changed into less-formal shoes and picked up a spare gun, just in case. If this man intended to chase him down, he’d make it difficult.

When the tram reached the end of the line, Duilio got off and began ambling toward the ships that bobbed on the river. He’d been to the area a few times in the past year, but wasn’t nearly as familiar with it as he would have liked. The man in the dark suit followed in a desultory manner, confirming Duilio’s suspicions.

The Church of Bom Jesus rose majestically in the midst of a public park. Duilio walked up the steps, stopped at the threshold of the church, and crossed himself. He’d been especially lax in his devotions since his brother’s death, one of those things he occasionally resolved to change, usually following one of Joaquim’s lectures. He waited a moment, allowing his eyes to adjust to the darkness and wondering if someone would come to renounce him. The lack of any divine rebuke reassured him.