"But you must explain," began Bernard, when he stopped. The boy had disappeared into the fog, and wondering how he came to be in possession of this information which concerned him, Gore walked along feeling his way by the brick wall. Perhaps Lucy had sent the message, and the Red Window was to be seen in the Crimea Square house. Bernard wished to ask the boy further questions, but the lad had vanished. In much perplexity the young man went down the hill towards Kensington High Street. As he paused at the corner wondering if it would be wise to go to the Square, and wondering also where it was, the boy suddenly appeared again at his elbow. "Come along acrost the road," he growled, and vanished again. Then Bernard got lost in the fog till the boy found him again. Bernard, not thinking any harm could come of the adventure, as he had ample confidence in his right arm, went across the street. The boy reappeared and led him down a side street. Gore tried to seize the boy and to detain him in order to ask questions, but the imp kept well out of reach, and only appeared when he thought there was danger of the tall soldier losing his way. In this manner Bernard was led down the quiet street, 'longside a high wall and through the heart of the dense fog. He kept his eyes open for any possible assailant, and did not feel the least afraid. All the same, he began to think he was foolish to follow on such a will-o'-the-wisp errand. But that the boy had mentioned the Red Window, Bernard would have turned on his heel. As it was, he felt curious enough to proceed. Suddenly the boy--a few feet ahead--led him into a wide space which was densely filled with fog. Here his guide turned to the right, and then whistled. When Gore, who had followed, heard that whistle he tightened his hold on his stick. The boy had vanished, and there he was alone in the heart of the fog. No one appeared, and he could not even see his guide. Looking overhead, Bernard suddenly saw a Red Window on the first story of a house. The house loomed hugely through the fog and was in some measure revealed by the light of a street lamp which threw a dull glimmer on to steps ascending to the door. There was a light behind the glass over the door, but the young man did not look at that. He was staring at the window in the first storey, which showed a fiery red color. "I wonder if this is Crimea Square and the house," muttered Bernard, stepping forward. "And whether Lucy put that light there, and sent the boy to tell me. But how could she know I was with Durham to-night?" Again he heard the whistle, and then came a shriek which apparently came from the house. Bernard ran to the steps, wondering if anything was the matter. The door opened, and a woman burst out of the house shrieking at the pitch of her voice--"Murder! Murder! Murder!" she cried. "Oh, the police--the police! Murder!"