But who? And how? Van Hupfeldt locked himself away from his valet--he lived in chambers near Hanover Square--and for hours sat without a movement, staring the stare of the hopeless and the lost. The fact that he had as good as won from Violet the pledging of herself to him--that fact which at another time would have filled him with elation, was now almost forgotten in the darkness of his calamity, as a star is swallowed up by clouds. The thing was known! That known which had been between the chamber of his heart and God alone! A bird of the air had whispered it, another soul shared in its horror. The faintest hiss of a wish to commit murder came from between his teeth. He had meant well, and ill had come; but because he had meant not badly and had struggled hard with fate, let no man dare to meddle! He could be flint against the steel of a man. His eyes, long bereft of sleep, closed of themselves at last, and he threw himself upon his bed. But the pang which pierces the sleep of the condemned criminal soon woke him. He opened his eyes with a clearer mind, and set to thinking. The unsigned note to Violet was in a man's hand. Some nights before in the cemetery he had found a man near the grave with her, and the man had seemed to be talking with her, a young, sunburned man. Who he was he had no idea; he had no reason to think this was the man who had sent the note. There was left only Miss L'Estrange. She might have sent it, getting a man to write for her--suspicion of itself fixed upon her. Always he had harbored this fear, that some paper, something to serve as a clue, had been left in the flat, which would lie hidden for a time, and then come forth into the noonday to undo him utterly. Gwendoline, he knew, had wished to screen him; but the chances were against him. He had never dared to go into the flat alone, to take the flat in his own name, and search it inside out. The place was haunted by a light step, and a sigh was in the air which no other ear could hear, but which his ear would hear without fail. Within those walls his eyes one night had seen a sight! He had not dared to take the place; but he had put Miss L'Estrange into it, and she had failed him; so, suspecting at last that she did not search according to the bargain, he had threatened to stop supplies, in order merely to spur her to search, for his heart had always foreboded that there was something to find.