A discreet knock on the door preceded Waverley's entrance with a report of the examination of every one in the house. He had gathered little beyond the fact that Grell, when not concerned in social duties, was a man of irregular comings and goings, and that Ivan, his personal valet, was a man he had brought from St. Petersburg, who spoke French but little English, and had consequently associated little with the other servants. Foyle subsided into his chair with his forehead puckered into a series of little wrinkles. He rested his chin on his hand and gazed into vacancy. There might be a hundred solutions to the riddle. Where was the motive? Was it blackmail? Was it revenge? Was it jealousy? Was it robbery? Was it a political crime? Was it the work of a madman? Who was the mysterious veiled woman? Was she associated with the crime? These and a hundred other questions beat insistently on his brain, and to none of them could he see the answer. He pictured the queer dagger, but flog his memory as he would he could not think where it might have been procured. In the morning he would set a score of men making inquiries at every place in London where such a thing was likely to have been obtained. He was in the position of a man who might solve a puzzle by hard, painstaking experiment and inquiry, but rather hoped that some brilliant flash of inspiration or luck might give him the key that would fit it together at once. They rarely do come. Once Lomont, Grell's secretary, knocked and entered with a question on his lips. Foyle waved him impatiently away. "I will see you later on, Mr. Lomont. I am too busy to see you now. Mr. Waverley or Mr. Bolt will see to you." The man vanished, and a moment or two later a discreet tap at the door heralded the return of Green, accompanied by Sir Ralph Fairfield. The baronet's hand was cold as it met that of Foyle, and his haggard face was averted as though to avoid the searching gaze of the detective. CHAPTER IV Fairfield, awakened from sleep by the news of the murder of his friend, had stared stupidly at the detective Foyle had sent to him. "Grell killed!" he exclaimed, "Why, he was with me last night. It is incredible--awful. Of course, I'll come at once--though I don't see what use I can be. What time was he murdered?" "About ten o'clock. So far as we know you were the last person to see him alive--except the murderer," said Green. "Believe me, we're sorry to have to trouble you." The baronet's face had suddenly gone the colour of white paper. A sickening dread had suddenly swept over him. His hands trembled as he adjusted his overcoat. He remembered that he had assured Lady Eileen that Grell had been with him at the club from six till eleven. What complexion would that statement bear when it was exposed as a lie--in the light of the tragedy? His throat worked as he realised that he might even be suspected of the crime.