“By a perfectly logical process. If Miss Marvell has had warning letters⁠—”

“Miss Marvell? She has been here?”

“She has just left. As I was saying, if she, as the holder of one of the twin diamonds, has received a mysterious series of warnings, you, as the holder of the other stone, must necessarily have done the same. You see how simple it is? I am right, then, you have received these strange communications also?”

For a moment she hesitated, as though in doubt whether to trust me or not, then she bowed her head in assent with a little smile.

“That is so,” she acknowledged.

“Were yours, too, left by hand⁠—by a Chinaman?”

“No, they came by post; but, tell me, has Miss Marvell undergone the same experience, then?”