"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.