"That's right," said Foyle. "But there are other ciphers where that system won't work. Mind you, I don't pose as an expert. If I had a cipher to unravel, I should go to a man who had specialised in them, exactly as I should go to a doctor on a medical question. Still, the advertisement to-day isn't a cipher. It means exactly what it says." "Thank you," said Fairfield drily. "I am now as wise as when I started." "Sorry," murmured Foyle suavely. "You'll be wiser presently. The thing isn't complete yet. If you'll excuse me a few minutes, I'll just run through my letters, and then, if you don't mind taking a little walk, we'll go and see Lady Eileen Meredith." Some formal reply rose to Fairfield's lips--he never knew what. The last time he had seen Eileen was fixed in his memory. Then she had practically denounced him as a murderer. Since then she had learnt that every shadow of suspicion had been cleared away from him. How would she receive him if he visited her unexpectedly with Foyle? Why did Foyle wish him to go? Perhaps, after all, there was nothing in it. He told himself fiercely that there was no reason why the meeting should embarrass him. Some day, sooner or later, they would have to meet. Why not now? He was hungry for a sight of her, and yet he was as nervous as a child at the thought of going to her. The slamming of a drawer and the soft click of a key in the lock told that Foyle had finished. He picked up a copy of the _Daily Wire_ and his hat and gloves. "Now, Sir Ralph," he said briskly, and together they descended the narrow flight of stone steps which leads to one of Scotland Yard's back doors. The detective was apparently in a talkative mood, and Fairfield got no chance to ask the questions that were filling his mind. Spite of himself he became interested in the flow of anecdotes which came from his companion's lips. There were few corners of the world, civilised or uncivilised, where the superintendent had not been in the course of his career. He had the gift of dramatic and humorous story-telling. He spoke of adventures in Buenos Ayres, in South Africa, Russia, the United States, and a dozen other countries, of knife-thrusts and revolver shots, of sand-bagging and bludgeoning, without any suspicion of vaunting himself. The baronet made some comment.