Drew back to whisper against her lips. “I’ll try to, if you’ll remember this. If you fail, we both will pay the price.”

She traced his lean cheek. Waited until he met her eyes. “I won’t fail. And neither will you.”

Their hearts were thudding; familiar flames licked hungrily over their skins. She searched his eyes. “This”—she shifted sinuously against him, felt his breath hitch—“was meant to be. We didn’t decree it, you or I, it was there, waiting to snare us. Now the challenge is to make all the rest work—it’s not an endeavor we can escape or decline, not if we want this.”

“I definitely want this, and more. I’m not letting you go. Not for any reason. Not ever.”

“So we’re committed, you and I.” She held his darkened gaze. “We’ll make it work.”

Two heartbeats passed, then he bent his head; his hands firmed, lifting her against him.

She dropped her hands to his shoulders, pressed back. “But…”

He paused, met her eyes. “But what?”

“But we’ve run out of time tonight.”

They had. Tristan tightened his arms, kissed her witless, then shackled his demons, clamoring for her, and, grim-faced, set her on her feet.

She looked as chagrined as he felt—a minor consolation.

Later.

Once they had Mountford by the heels, nothing was going to get in their way.

His carriage was waiting; he escorted Leonora out to it, helped her in, and followed. As the carriage rattled off over the now wet cobbles, he returned to something she’d mentioned earlier. “Why does Humphrey think pieces of Cedric’s puzzle are missing? How can he know?”

Leonora settled back beside him. “The journals are details of experiments—what was done and the results, nothing more. What’s missing is the rationale that makes sense of them—the hypotheses, the conclusions. Carruthers’s letters refer to some of Cedric’s experiments, and others which Humphrey and Jeremy reason must be Carruthers’s own, and the sheets of descriptions from Carruthers we found in Cedric’s room—Humphrey thinks at least some of those match some of the experiments referred to in Carruthers’s letters.”

“So Cedric and Carruthers appear to have been exchanging details of experiments?”

“Yes. But as yet Humphrey can’t be certain whether they were working on the same project together, or whether they were simply exchanging news. Most pertinently, he hasn’t found anything to define what their mutual project, assuming there was one, was.”

He juggled the information, debating whether it made Martinbury, Carruthers’s heir, more or less important. The carriage slowed, then halted. He glanced out, then climbed out before Number 14 Montrose Place and handed Leonora down.

Overhead, the clouds were scudding, the dark pall breaking up before the wind. She tucked her hand into his arm; he glanced at her as he swung the gate wide. They walked up the winding path, both distracted by the eccentric world of Cedric’s creation gleaming in the fitful moonlight, the odd-shaped leaves and bushes embroidered with droplets of rain.

Light beamed from the front hall. As they climbed the porch steps the door swung open.

Jeremy looked out, his face tense. He saw them and his features eased. “About time! The blackguard’s already started tunneling.”

In absolute silence, they faced the wall beside the laundry trough in the basement of Number 14 and listened to the stealthy scritch-scritch of someone scraping away mortar.

Tristan motioned Leonora and Jeremy to stillness, then put out a hand, and laid it on the bricks from behind which the noise was emanating.

After a moment, he removed his hand and signaled them to retreat. At the entrance to the laundry, a footman stood waiting. Leonora and Jeremy went silently past him; Tristan paused. “Good work.” His voice was just loud enough to reach the footman. “I doubt they’ll get through tonight, but we’ll organize a watch. Close the door and make sure no one makes any unusual sound in this area.”

The footman nodded. Tristan left him and followed the others into the kitchen at the end of the corridor. From their faces, both Leonora and Jeremy were bursting with questions; he waved them to silence and addressed Castor and the other footmen, all gathered and waiting with the rest of the staff.

In short order he organized a rotating watch for the night, and reassured the housekeeper, cook, and maids that there was no likelihood of the villains breaking in undetected while they slept.

“At the rate they’re going—and they’ll have to go slowly—they can’t risk a hammer and chisel—they’ll take at least a few nights to loosen enough bricks to let a man through.” He glanced around the company gathered about the kitchen table. “Who noticed the scratching?”

A tweeny colored and bobbed. “Me, sir—m’lord. I went in to get the second hot iron and heard it. Thought it was a mouse at first, then I remembered what Mr. Castor had said about odd noises and such, so I came straightaway and told him.”

Tristan smiled. “Good girl.” His gaze rested on the baskets piled high with folded sheets and linens set between the maids and the stove. “Was it washing day today?”

“Aye.” The housekeeper nodded. “We always do our main wash on a Wednesday, then a small wash on Mondays.”

Tristan looked at her for a moment, then said, “I have one last question. Have any of you, at any time in the last several months, going back to November or so, seen or been spoken to by either of these two gentlemen?” He proceeded to give quick word sketches of Mountford and his weasely accomplice.

*   *   *

“How did you guess?” Leonora asked when they were back in the library.

The two older maids and two of the footmen had been approached independently at various times in November, the maids by Mountford himself, the footmen by his accomplice. The maids had thought they’d found a new admirer, the footmen a new and unexpectedly well-heeled acquaintance always ready to buy the next pint.

Tristan dropped onto the chaise beside Leonora and stretched out his legs. “I always wondered why Mountford tried first to buy the house. How did he know Cedric’s workshop had been locked up and left essentially undisturbed? He couldn’t see in—the windows are so old, so fogged and crazed, it’s impossible to see anything through them.”

“He knew because he’d cozened the maids.” Jeremy sat in his usual place behind his desk. Humphrey was in his chair before the hearth.

“Indeed. And that’s how he’s known other things”—Tristan glanced at Leonora—“like your propensity to walk alone in the garden. At what times you go out. He’s been focused on this household for months, and he’s done a decent job of reconnoitering.”

Leonora frowned. “That begs the question of how he knew there’s something here to be found.” She looked at Humphrey, one of Cedric’s journals open on his lap, a magnifying glass in his hand. “We still don’t know there’s anything valuable here—we’re only surmising because of Mountford’s interest.”

Tristan squeezed her hand. “Trust me. Men like Mountford never are interested unless there’s something to gain.”

And the notice of foreign gentlemen was even less easy to attract. Tristan kept that observation to himself. He looked at Humphrey. “Any advance?”

Humphrey spoke at length; the answer was no.

At the end of his explanation, Tristan stirred. They were all keyed up; sleep would be difficult knowing that in the basement, Mountford was quietly excavating through the wall.

“What do you expect to happen now?” Leonora asked.

He glanced at her. “Nothing tonight. You can rest easy on that score. It’ll take at least three nights of steady working to open a hole big enough for a man without alerting anyone on this side.”

“I’m more worried about someone on this side alerting him.”

He smiled his predator’s smile. “I have men all around—they’ll be there night and day. Now Mountford’s in there, he won’t get away.”

Leonora looked into his eyes; her lips formed a silent O.

Jeremy humphed. He picked up a sheaf of the papers they’d found in Cedric’s room. “We’d better get on with these. Somewhere here, there has to be a clue. Although why our dear departed relative couldn’t use some simple, understandable cross-referencing system I don’t know.”

Humphrey’s snort was eloquent. “He was a scientist, that’s why. Never show any consideration for whoever might have to make sense of their works once they’re gone. Never come across one who has in all my days.”

Tristan stood, stretched. Exchanged a glance with Leonora. “I need to think through our plans. I’ll call tomorrow morning and we’ll make some decisions.” He looked at Humphrey, included Jeremy when he said, “I’ll probably bring some associates with me in the morning—can I ask you to give us a report on what you’ve discovered up to then?”

“Of course.” Humphrey waved. “We’ll see you at breakfast.”

Jeremy barely glanced up.

Leonora saw him to the front door. They stole a quick, unsatisfying kiss before Castor, summoned by some butlerish instinct, appeared to open the door.

Tristan looked down into Leonora’s shadowed eyes. “Sleep well. Believe me, you’re at no risk.”

She met his eyes, then smiled. “I know. I have proof.”

Puzzled, he raised a brow.

Her smile deepened. “You’re leaving me here.”

He searched her face, saw understanding in her eyes. He saluted her, and left.

By the time he reached Green Street, his plan was clear in his mind. It was late; his house was quiet. He went straight to his study, sat at his desk, and reached for his pen.