He traces the I column until B is reached; the first letter in that line, T, is the first letter of the message—­and so on.

Simple!  Yes, childishly simple with the key-word; and the key-word can be carried in one’s mind.  Without the key-word, translation is impossible.

Harleston put down the paper and leaned back.

Altogether it was a most interesting collection, these four articles on the table.  It was a pity that the cab and the sleeping horse were not among the exhibits.  Number one:  a lady’s lace handkerchief.  Number two:  three American Beauty roses, somewhat the worse for wear and violent usage.  Number three:  a cipher message.  Number four:  photograph of Madame—­or Mademoiselle—­de Cuthbert, de Spencer, de Lotzen.  There was a pretty plot behind these exhibits; a pretty plot, or he missed his guess.  It might concern the United States—­and it might not.  It would be his duty to find out.  Meanwhile, the picture stirred memories that he had thought long dead.  Also it suggested possibilities.  It was some years since they had matched their wits against each other, and the last time she rather won out—­because all the cards were hers, as well as the mise en scene.  And she had left—­

His thought trailed off into silence; and the silence lasted so long, and he sat so still, that the ash fell unnoticed from his cigarette; and presently the cigarette burned itself into the tip, and to his fingers.

He tossed it into the tray and laughed quietly.

Rare days—­those days of the vanished protocol and its finding!  He could almost wish that they might be again; with a different mise en scene, and a different ending—­and a different client for his.  He was becoming almost sentimental—­and he was too old a bird for sentiment, and quite too old at this game; which had not any sentiment about it that was not pretence and sham.  Yet it was a good game—­a mighty entertaining game; where one measured wits with the best, and took long chances, and played for high stakes; men’s lives and a nation’s honour.

He picked up the photograph and regarded it thoughtfully.

“And what are to be the stakes now, I wonder,” he mused.  “It’s another deal of the same old cards, but who are players?  If America is one, then, my lady, we shall see who will win this time—­if you’re in it; and I take it you are, else why this picture.  Yet to induce you to break your rule and cross the Atlantic, the moving consideration must be of the utmost weight, or else it’s purely a personal matter.  H-u-m!  Under all the circumstances, I should say the latter is the more likely.  In which event, I may not be concerned further than to return these—­” with a wave of his hand toward the exhibits.

For a while longer he sat in silence, eyes half closed, lips a bit compressed; a certain sternness, that was always in his countenance, showing plainest when in reflective thought.  At last, he smiled.  Then he lit another cigarette, took up the letter and the photograph, and put them in the small safe standing behind an ornate screen in the corner—­not, however, without another look at the calmly beautiful face.