“I see. And how did you deduce from this recognition that the subsequent note on the same piece of paper was written by Mr. Ballinger?”

“Because Mrs. Burroughs said she gave the list to Lady Rathbone to purchase the—”

There was another explosion of sound in the courtroom.

The judge banged his gavel and commanded silence, on pain of people’s forcible removal from the room.

Rathbone felt the heat sear up his face until he could hardly breathe. He did not dare look at Margaret, or her family, although he knew exactly to the inch how far he would have to turn his head to do so.

“To purchase the medicines from the apothecary,” Monk continued. “Which Lady Rathbone did, for she gave the receipts to Mrs. Burroughs but did not return the original list. It seems reasonable, even inevitable, to assume that she discarded it where Mr. Ballinger, her father, found it and tore off a piece to use for this note to Parfitt, not knowing that what was on the back was so distinctive.”

“I see,” Winchester said gravely. “And did you subsequently ask Mr. Ballinger to account for his whereabouts that evening?”

“Yes, sir,” Monk replied. “He never pretended that he was not in the area, but he did say that he was in Mortlake, some short distance up the river from Corney Reach, where the body was found. He was in the company of a friend, which the friend verified. However, it is possible, if you are a strong rower, to take a boat from Mortlake to Corney Reach and come back again, then catch a hansom at the south side of the river to the ferry where Mr. Ballinger originally crossed, all in the time that he stated and his friend confirmed.”

“Really?” Winchester affected surprise. “Are you sure?”

“Yes, sir. I did it myself, at the same time of the evening.”

“Remarkable. Thank you, Commander Monk.” Winchester turned to Rathbone with a smile.

Rathbone rose to his feet with a very slight tremble in his hands. He had just realized an astounding possibility. Neither Monk nor Winchester had mentioned Hattie Benson, either by name or occupation. Was that to spare Lord Cardew’s feelings? Or had she withdrawn her testimony, refusing now to take the stand? Without her, Rupert was still a prime suspect.

Could he discredit this wretched note somehow? Suggest it had a different date, a different meaning? Even that it had originally been addressed to someone else?

He needed time.

“It is late, my lord,” he said with exaggerated courtesy. “I have several questions to ask Mr. Monk, of fundamental importance to the whole case—things that may lead us in an extremely different direction. I would prefer, out of respect to yourself and the jury, to begin this when there is the opportunity to carry the matter to its conclusion.”