“Eh,” exclaimed that gentleman, genuinely astonished. “Does she take me for a greater fool than you?”

I waved to him to be silent.

“Ask him what woman would do most to prevent the duke from marrying his cousin, and therefore most to prevent him becoming king? And ask if her name begins with—A?”

I sprang to my feet. Sapt laid down his pipe.

“Antoinette de Mauban, by heaven!” I cried.

“How do you know?” asked Sapt.

I told him what I knew of the lady, and how I knew it. He nodded.

“It’s so far true that she’s had a great row with Michael,” said he, thoughtfully.

“If she would, she could be useful,” I said.

“I believe, though, that Michael wrote that letter.”