“He has no proof where he was.” Runcorn put down his cup and touched the points off on his fingers. “He had the opportunity to have been in Cuthbert Street. He resembles the figure seen on the roof by the witnesses. Only an impression, but elegant, dark, taller than she was, but not by a great deal. But she was quite a tall woman.” Runcorn held up his second finger. “He needed nothing to kill her with except his own weight and strength. And of course there was the man’s coat button we found in her hand. We’ll look at all his clothes.”

Monk felt the chill run through him and then the sweat break out on his body. He prayed Runcorn did not notice it. The jacket with the missing button was in his wardrobe in the bedroom. Thank God he had not stuffed it into the stove with the paper. He had thought about it!

“Hope he hasn’t destroyed it,” Runcorn went on. “But even if he has, people will know he had another coat, and how will he explain its disappearance?”

Monk said nothing. His mouth was dry. Where could he find another button and replace it? If he went to a tailor Runcorn might find out.

Runcorn held up a third finger. “And she had accused him of being involved in fraud; we know that she hired you to prove it!”

Monk licked his lips.

“Disprove it, actually,” he countered.

“And he wanted to cast her aside and marry the Baltimore heiress,” Runcorn went on relentlessly. “That’s more than motive enough.”

Hester was looking silently from one to the other of them.

“Only if we prove the land fraud,” Monk argued. “And Livia Baltimore is probably quite comfortably off, but she’s not an heiress.”

“She will be when Baltimore and Sons sells its railway components to India,” Runcorn answered vehemently. “It will make them all rich, and it will only be the beginning. The money will go on and on.”

Something flickered in Monk’s brain, then vanished.

“What is it?” Runcorn demanded, looking at him more closely.

Monk sat motionless, trying to bring it back, to catch something of it from the edge of his mind, but it was gone. “I don’t know,” he admitted.

Anger flared for an instant in Runcorn’s eyes, then was replaced by understanding. “Well, if you remember, tell me. In the meantime, I’ve got to tie Dalgarno into the fraud better.” His tone of voice had a lift at the end, as if waiting for Monk to complete the thought for him.

“I’ll help,” Monk said immediately. It was a statement. He intended to whether Runcorn agreed or not; it would simply be easier if he did.

Runcorn must have searched the rest of Katrina’s house. Had he found any letters from Emma? There would be a return address on them. Dare he ask? What excuse could he give?