“She has deserted me, sir,” Sir Anthony replied. “Miss Grayson has the migraine, and Miss Merriot has taken her off to find her aunt.”

“Indeed?” said my lord, and proffered his snuff-box. Mr Markham’s late exit with Miss Letty had not escaped that eagle eye.

A gentle touch on his sleeve made Sir Anthony turn round. Prudence stood at his elbow, and smiled shyly as he looked down at her. “Have you lost my sister, sir? I saw you a while back flirting prodigiously with her. It’s a sad piece, I believe.”

Sir Anthony walked apart with her. “It is,” he agreed. “How came you by so impertinent a brother, my dear?”

Prudence chuckled. “You’ve met the old gentleman, Tony. Don’t you perceive the resemblance? Robin is a rogue.”

“I’m of the opinion he’s a young hothead. I asked him tonight, as the thought occurred to me, whether he knew anything of a Black Domino, calling himself l’Inconnu.”

“And does he?” asked Prudence innocently.

“It’s in my mind,” said Sir Anthony slowly, “that you’re a fitting pair. Is there nothing of the rogue in Peter Merriot?”

“Oh, sir, it’s a most sober youth.”

Came the rustle of silks; Robin swirled down upon them, gracefully fanning himself. “What, my Peter! You’ll make a third, will you? I vow, ’tis unkind in you!”