The department's search at the newspaper office resulted in the finding of no less than sixteen earlier advertisements inserted by Mrs. Beecher Monmouth. In each case, only a box number was given, therefore the lady's identity never became public.
"It looks as if you are on the right track, Treves," said Dacent Smith, when this information was conveyed to him on the telephone.
Half an hour later Dacent Smith, again at the telephone, took down the decoded first advertisement, the one wherein Mrs. Beecher Monmouth had advertised a pearl pendant for sale. John's chief wrote it out carefully, and handed the slip across to the younger man.
"There is your advertisement, Treves," he exclaimed. There was a grave ring in his voice. John took the slip of paper and read:
"Note of Warning.—New standard eight thousand ton ship purposely advertised by shipping authorities here as fitting out at —— is a 'Q' ship, armed with six-inch guns, torpedo tubes are being fitted. Further news in next message."
John looked up from the pencilled lines. He saw in a flash the exact purport of the message. Mrs. Beecher Monmouth in pretending to advertise a pearl pendant was in reality sending a message to Germany to the effect that a certain vessel then building was a decoy ship, one of the famous vessels which had done so much to break the back of the submarine peril. John could easily realise how swiftly that news would reach Germany. Automatically the paper would reach Holland within two days. Any neutral ship might carry copies, and Berlin's Naval Department would possess the information a few minutes after the daily paper containing Mrs. Beecher Monmouth's advertisement reached Dutch soil. Every German spy in England who read the newspaper would receive the news on the morning of its insertion.
"I think for cunning that beats everything," said John, handing back the paper to Dacent Smith.
"They have been preparing this sort of thing for years," answered Dacent Smith. "But I am willing to admit that Mrs. Monmouth has this time stolen something of a march on us.
"Every one of her advertisements is being decoded, however, and every one, I have no doubt, will convey information of this nature. On the other hand," he said, "we have not yet learnt in what manner she communicated with the submarine that sunk the Malta, That must have been a much quicker communication. I shall leave it to you, Treves," he said quietly, "to find out what that method is. You will have to learn much more of Mrs. Beecher Monmouth than we know already. The fight is quickening between us. And the big fight which von Kuhne is planning in the Isle of Wight is not quite so indefinite to us as it was. The date at least is in our possession. And by then," he went on, "all the carrion will have wended their way there, even our friend, Mrs. Beecher Monmouth, will be there by then." John looked at him in sudden surprise.
"I thought she was seldom out of London, sir."