She turned to Hester. “And you also, Miss Latterly. I can only apologize to you for involving you in our family’s tragedy. I hope that word of it has not reached London in the detail it has been reported here, and it will not affect your life or your livelihood, as Quinlan supposes. If I could undo it for you, I would, but it is beyond my power. I am sorry.”

“We all regret it,” Hester said quietly. “You should feel no need to apologize, but I thank you for your gracious-ness. I knew Mrs. Farraline for only a very brief time, but from her conversation that evening on the train, I choose to believe as you do, and do not find it in the least difficult”

Oonagh smiled, but there was no answer in her eyes, no relief from the tension there.

As soon as the meal was over Monk seemed in some haste to depart.

“I shall leave the matter in your hands,” he said to Alastair. “You are aware of your mother’s property, and of the disposition of it, and of Arkwright’s tenancy. You must inform the police of whatever you think appropriate. As Procurator Fiscal, you are far better placed than I to judge what is evidence and what is not.”

“Thank you,” Alastair accepted gravely, but also apparently without relief. “Good-bye, Mr. Monk, Miss Latterly. I hope your journey back to London is agreeable.”

As soon as they were out of the door and on the pavement, Monk pulling his collar higher and Hester wrapping her blue coat tighter around her against the wind, Monk spoke.

“I’m damned if I’m finished yet! One of them killed her. If it wasn’t Mclvor, it was one of the others.”

“I would dearly like it to be Quinlan,” Hester said with feeling as they crossed the road and stepped onto the grass. “What a perfectly odious man. Why on earth did Eilish marry him? Any fool can see she loathes him now-and little wonder. Do you think Hector was drunk?”

“Of course he was drunk. He’s always drunk, poor old devil.”

“I wonder why,” she said thoughtfully, increasing her speed to keep up with him. “What happened to him? From what Mary said, he used to be every bit as dashing as Hamish, and a better soldier.”

“Envy, I suppose,” he replied without interest. “Younger brother, lesser commission, Hamish got the inheritance, and appears to have had the brains as well, and the talent.”

They reached the far side of the Place and turned down Glenfinlas Street.

“I meant do you think he was so drunk he was talking nonsense?” she resumed.

“About what?”

“A secret room, of course,” she replied impatiently, having to run again to keep at his side, and brushing past a woman with a basket. “Why would Hamish build a secret room in a printing works?”

“I don’t know. To hide illegal books?”

“What sort of books would be illegal?” she asked breathlessly. “You mean stolen ones? But that doesn’t make any sense.”

“No, of course not stolen ones. Seditious-blasphemous- most probably pornographic.”

“Oh-oh I see.”

“No you don’t. But possibly you understand.”

She did not quibble. “Is that worth killing over?”

“If it was graphic enough, and there was enough of it,” he replied. “It could be worth a lot of money.”

Two gentlemen crossed the street ahead of them, one swinging a cane.

“You mean they could sell it for a lot.” She could be equally pedantic. “It’s worth nothing.”

He pulled a face. “Didn’t think you’d know what it was.”

“I’ve been an army nurse,” she said tartly.

“Oh.” For a moment he was confused, off balance. He did not wish to think of her as being aware of such things, much less to have seen them. It offended him. Women, especially decent women, should never have to see the obscenities of the darkest human imagination. Unconsciously he increased his speed, almost knocking into a man and woman. The man glared at him and muttered something.

Hester was obliged to break into a trot to keep up.

“Are we going to look for it?” she asked, gasping. “Please slow a little. I cannot speak or listen at this rate.”

He obeyed abruptly and she shot a couple of paces past him.

“I am,” he answered. “You’re not.”

“Yes I am.” It was a single, contradictory, pigheaded statement. There was no question or pleading in it.

“No you are not. It may be dangerous…”

“Why should it? They said there would be no one there tomorrow, and there certainly won’t be today. They’d never break the Sabbath.”

“I’m going tonight, while it’s dark.”

“Of course we are. It would be absurd to go in the daylight; anyone might see us.”

“You’re not coming!”

Now they were stopped and causing an obstruction on the footpath.

“Yes I am. You’ll need help. If it really is a secret room, it won’t be all that easy to find. We may have to knock for hollow places, or move-”

“All right!” he said. “But you must do as you’re told.”

“Naturally.”

He snorted, and once again set off at a rapid pace.

It was a little before eleven, and pitch-dark except for the lantern which Hester held, when she and Monk finally stood in the huge print room and began their task. To avoid unnecessary noise they had had to break in. It had taken some time, but Monk possessed skills in that field which startled Hester, though he offered no account of how he had come by them. Possibly he did not recall himself.

For over an hour they searched, slowly and methodically, but the building was very solidly and plainly built. It was simply a barnlike structure, similar to the warehouses on either side of it, for the purpose of printing books. There was no ornament or carving, no alcoves, mantels, sets of shelves or anything else which could mask an opening.

“He was drunk,” Monk said in disgust. “He just loathed Hamish so much he was trying to make trouble, anything he could think of, no matter how absurd.”

“We haven’t been searching very long yet,” she argued.

He gave her a withering look, which was exaggerated by the yellow glare of the lantern and the black cavern above them.

“Well, do you have a better idea?” she demanded. “Do you just want to go back to London and never know who killed Mary?’

Wordlessly he turned back to reexamine the wall.

“It’s straight along the line of the abutting wall onto the next warehouse,” he said half an hour later. “There isn’t any space for a secret compartment, let alone an entire room.”

“What if it’s in the roof?” she said desperately. “Or the cellar?”

“Then there’ll be stairs to it-and there aren’t.”

“Then it must be here. We just haven’t found it.”

“Your logic is typical,” he said tartly. “We haven’t found it, so it must be here.”

“That’s not what I said. You have it backwards.”

He raised his eyebrows. “It must be here because we haven’t found it? That is a deductive improvement?”

She took the lantern and left him standing in the dark. There was nothing to lose by searching a little longer. This was the last chance. Tomorrow they would leave, and either Baird Mclvor would face trial, and maybe be hanged, or else live with another “not proven” verdict over his head. Either way, she would never be sure who had killed Mary. She needed to know, not just for herself but because Mary’s wry, intelligent face was still as sharp in her mind as when she had gone to sleep that night on the train to London, thinking how very much she liked her.

She did not find it by accident, but by methodical, furious banging and thumping. A heavy panel of the wall slid away and opened up a narrow door. The room itself must originally have been part of the nextrdoor warehouse and not the Farraline building at all. Its very existence was concealed because a floor plan would have shown no discrepancy. One would have had to have the plans of both buildings and compare them.

“I’ve got it!” she cried out exultantly.

“Don’t shout,” he whispered from just behind her, making her start and nearly drop the lamp.