Gimblet leant out of the window and watched the barge negotiate the bridge. Then he returned to his chair, and taking Lord Ashiel's envelope out of his pocket looked it over thoughtfully before opening it. He had no doubts as to what it contained; he had been on the point of reminding the peer that he had forgotten to give him the key of the cipher he had spoken of when the widow's ring at the door had driven him to a hurried retreat, but he had not considered the omission of any particular significance. His client would certainly discover it and either return to give him the key, or send it to the flat. It would probably be some time before it was required for use here. In the meantime, thought Gimblet, he would have a look at it before locking it away in the safe. He turned over the envelope. To his surprise, the flap was open and the glue had obviously never been moistened. It was the work of an instant to look inside, but almost quicker came the conviction that it was useless to do so. He was not mistaken. The envelope was empty. Gimblet stared at it for one moment in blank dismay. Then he strode to the door and shouted for Higgs. "Did you notice," he asked him, "whether the envelope Lord Ashiel gave you for me was fastened, or was it open as this one is?" "Oh no, sir," replied Higgs, "it was sealed up. There was a large patch of red sealing-wax at the back, with a coronet and some sort of little picture stamped on it. I can't say I looked at it particularly, but there may have been a lion or a dog, or some kind of animal. His lordship's arms, no doubt" "You are quite certain about the sealing-wax?" Gimblet repeated slowly. "Yes, sir, I am quite certain about that," answered Higgs; and he could not refrain from adding, "I put down the note on this little table, sir, as you told me." "Thank you. That is all." Gimblet's tone was as undisturbed as ever, but inwardly he was seething with anger and disgust; directed, however, entirely against himself. When Higgs had departed he allowed himself the unusual, though quite inadequate relief of giving the chair on which his last visitor had sat a violent kick. After that he felt rather more ashamed of himself than before, if possible, and he sat down and raged at the simple way in which he had been fooled. The widow had taken the envelope, of course. She must have snatched it up during the few seconds he had turned his back on her in order to step across the hall and retrieve her bag, and have replaced it at the same instant with this empty one which she had no doubt taken from his own writing-table while he stooped beside her to pick up her glove. Gimblet fetched one of his own blue envelopes and compared it with the substitute. Yes, they were alike in every particular. The watermarks were the same and showed that she had used what she found ready to her hand.