THE WHODUNIT COLLECTION: British Murder Mysteries (15 Novels in One Volume). Charles Norris Williamson

his own judgment as to how much of the interview he should communicate to the detective, and with this Foyle had to be content.

      The baronet found the girl waiting for him, her face alight with eagerness. She was in her own boudoir, luxuriously ensconced in a big arm-chair, and she smiled brightly at him—such a smile as he had not seen since before the murder. He obeyed her invitation to sit down.

      "You wanted to see me alone," he said.

      She nodded. "Yes, I want to know if we are allies—or enemies. I know I have treated you abominably, but I was driven half mad by the thought that Bob was dead. Now we are working together—are we not?"

      He made a little gesture with his hands, helplessly as one at a loss.

      "In so far as we both wish to get Grell out of his difficulty—and I wish I knew what that was—yes," he replied. "I don't believe him to be a murderer, but why does he remain in hiding? He is not the sort of man to do foolish things, and that is foolish on the face of it. He has some strong reason for being out of the way. Can you explain?"

      She pulled her chair closer to him, and laid one slim hand on his.

      "I cannot explain—I can only trust. He looked to us to help him. I know that he wants money, for he sent a friend to tell me. I had none, but I gave her my jewels. Detectives were watching her, and they, with the connivance of my father, took them from her. Now, you, his most intimate friend, must help him. He has given you the key to the cipher which will appear, and then, I suppose, he will tell you how to get it to him."

      She had apparently taken it for granted that the baronet was with her in whole-souled devotion to her lover. His fingers beat a tattoo on his knee.

      "So that advertisement was the key to a cipher? Do you know when I shall get a message?"

      "I shall get one to-morrow. You—who knows?"

      "Then you can tell me how to read it?"

      She hesitated a moment, finger on chin. Then, animated by a quick resolve, she moved to a little inlaid desk and unlocked a drawer. She returned with a piece of paper in her hand.

      "What was the number mentioned in your advertisement?"

      "2315."

      For a little the only sound in the room was the scratching of pencil on paper. At last she finished, and handed the result to him. He wrinkled his brows as he studied it.

THIS	IS	THE	KEY
2315	23	152	315
VKJX	KV	UMG	NFD

      "The bottom line is the top one turned into cipher," she explained. "The middle line is the key number. In the first word you take the second letter from T, the third from H, the first from I, and so on. It is a cipher that cannot be unravelled without the key number. H becomes K once and M once."

      "I see." The simplicity of it at once dawned on him. "That was what Foyle meant when he said that some ciphers could not be solved by the recurring E," he said unthinkingly.

      She had risen and flung away from him in quick revulsion. One glance at her face told him what he had done.

      "You spy!" There was stinging scorn in her tone. "You have talked it over with Foyle, and that man knows all. You are here to worm out what I know in order to betray your friend. Oh, don't trouble to lie,"—as he would have spoken,—"I can see your object. And I nearly fell into the trap."

      The man was not without dignity, as he stood a little white but steady. "You may call me what you like," he said in a low voice. "Spy, if you will. Believe me or not, I have acted for the best, for you and for Grell. You once called me a murderer—with what justification you now know. Are you so ready to judge hastily again?"

      If he had hoped to move her from her gust of passion, he quickly learned his mistake. Her lips curled in contempt, and, drawing her skirts aside as she passed him as though a touch might contaminate her, she swept to the doorway. For one instant she stood posed.

      "You call yourself a spy. It is a good name. For a police spy there is no room in this house."

      With that she was gone. The man had flushed under the biting contempt in her voice and words, and now stood for a little with hands tightly clenched, gazing after her. He felt that, from her point of view at least, there was some truth in her words. He was—whatever his motives—a police spy. And yet he was but concerned to clear up the horrible tangle in which his friend and the girl had become involved.

      He did not know that he was watched from behind the curtains as he walked blindly into the street. Eileen, with lips firmly set and face tense, was concealed behind curtains. No sooner had he gone than she hurriedly dressed herself and ordered an electric brougham. She had come to believe that her lover's safety depended on her actions that day. Foyle knew the secret of the cipher, and Grell's advertisement told her that he intended communicating something to her by that method the next day. At all costs she must prevent him betraying himself.

      Only one course occurred to her. She must go to the office of the Daily Wire and prevent his advertisement from appearing. How she was to do it she had not the slightest idea. That she left for later reflection.

      The car rolled smoothly towards Fleet Street, but no inspiration came to her. She alighted at the advertisement office, with its plate glass and gilded letters, and was attended by an obsequious clerk. Outwardly calm, but with her heart beating quickly beneath her furs, she put her inquiry to a sleek-haired clerk. He was polite but firm. It was quite possible that such an advertisement as she mentioned had been sent for insertion the following day, and again it might not. In any case he was forbidden to give any information. It would be quite out of the question to stop any advertisement unless she held the receipt.

      "But if the advertisement has not already been given in, can you give a note to whoever brings it?" she asked, in a flash of inspiration.

      "Yes, that could be done." She tore off her glove, and with slim, nervous fingers wrote hurriedly. The sleek clerk supplied her with an envelope, and as she placed her message in it and handed it to him she felt it was a forlorn hope. There was only one other way of outwitting the detectives. Should Grell give any address in his message, she must reach him early in the morning before the police could act. A couple of questions elicited the fact that the paper would be on sale by four the next morning. That would mean another journey to Fleet Street, for the ordinary news-agents' shops would not be open at that time. The brougham turned about and began the homeward journey.

      A respectably dressed working man, who had apparently been absorbed in a page of advertisements of situations vacant displayed on a slab in the window, slouched into the office, and a man bareheaded and wearing a frock-coat moved briskly forward, apparently to attend to him. Yet it was more than coincidence that they met at a deserted end of the counter.

      "That was Lady Eileen Meredith," said the workman, in a quick, low voice. "What did she want?"

      "She's guessed that we know the cipher," retorted the other. "She gave a letter to be handed over to whoever brings the advertisement. Here is what she says." He pulled the letter which Eileen had written five minutes before from its envelope: "'The police know the cipher. Be very cautious. R. F. is acting with them.' I'll telephone to Mr. Foyle at once. You had better stay outside."

      The second man went back to the pavement and resumed his study of the advertisement board, but a close observer might have seen that his eyes wandered past it now and again to the persons inside the office. Half an hour went by. Then the frock-coated man inside took a silk hat from a peg and placed it on his head. Simultaneously a woman went out. A dozen paces behind her went the workman, and a dozen paces behind