“Li Chang Yen may be regarded as representing the brains of the Big Four. He is the controlling and motive force. I have designated him, therefore, as Number One. Number Two is seldom mentioned by name. He is represented by an S with two lines through it⁠—the sign for a dollar; also by two stripes and a star. It may be conjectured, therefore, that he is an American subject, and that he represents the power of wealth. There seems no doubt that Number Three is a woman, and her nationality French. It is possible that she may be one of the sirens of the demimonde, but nothing is known definitely. Number Four⁠—”

His voice faltered and broke. Poirot leant forward.

“Yes,” he prompted eagerly, “Number Four?”

His eyes were fastened on the man’s face. Some overmastering terror seemed to be gaining the day; the features were distorted and twisted.