"There's only one thing that wasn't spoken of," said Quex, when he saw the boarders in the drawing-room for the last time; "it seems that Mrs. Jersey always put out the light above the door at eleven, or when the guests departed. On this occasion it burned all night, and, as it shines behind crimson glass, such a red window might be a guide to any one who did not know the house, but who had been given that sign whereby to distinguish it." "I can explain that," said Granger, who was present. "When Madame was bidding farewell to her guests she thought that some of them might be lost in the fog. Therefore she called out after them that she would let the light burn later so that any might be able to retrace their steps." "Well," said Quex, scratching his head, "that explanation is clear." "And there is no use for it," put in Miss Bull, "since the front door was locked and no one entered the house on that night." "That's just it," said the inspector, sagaciously. "As all you ladies and gentlemen are clearly innocent the crime must have been committed by some one from outside. Now, is there any one to whom Madame gave a latch-key?" "None of us had latch-keys," said Harmer. "Madame would not allow such a thing." "Oh, I don't mean you, or those like you, Mr. Harmer. At your age a latch-key is not necessary. But Mrs. Jersey may have given one to a friend of hers who came to see her on that night. Had she any friend in whom she would place such confidence?" "No," said Miss Bull, decisively. "She trusted no one that far. And I don't think she had a single friend outside this house." "And very few in it," muttered Mrs. Taine, who on various occasions had suffered from Madame's tongue. "In that case," said Quex, rising to take his leave, "there is nothing more to be discussed. Who killed Mrs. Jersey, or why she was killed, will probably never be known. Ladies and gentlemen, good-day," and the inspector bowed himself stiffly out of the room, with the air of a man who washed his hands of the whole concern. And, after all, what could he do? There was no proof likely to indicate any one as the assassin, and since Leonard kept silent on the point of the front door having been opened after eleven, it was impossible to say that the criminal had entered the house. Had Mr. Inspector known of this he might have made further inquiries; but he knew nothing and departed extremely perplexed. The Amelia Square crime was one of those mysterious murders which would have to be relegated to obscurity for sheer want of evidence. "When are you going back to Duke Street?" asked Brendon as he took his leave of Train. "This very day," replied the young man, gloomily. "I don't want to stop a moment longer than I can help in this awful house." "I expect many of the others are of your way of thinking, Train. But, so far as I can see, there is no hope of learning who killed the woman."