The secretary coughed deprecatingly. He was slightly surprised and pained to think that his worthy chief had not heard of the famous Secret Service agent. "Oh, yes; now I do," corrected the Commander-in-Chief. "He was barging about down in Cornwall over that von Gobendorff case, when I was Senior Officer at Trecurnow. Well, what is it now?... By Jove!" The telegram had been dispatched from York. It read as follows:-- "To S.N.O., Auldhaig. For your information and necessary action:--Discover Captain Fennelburt, R.A.F., to be Leutnant Karl von Preussen (_vide_ dossier 445). He has dispatched the following cablegram to Admiralty, Berlin: 'Q-boat disguised as U 251 left Leith on 9th for Hoorn Reefs." "Someone's let the cat out of the bag," declared the Commander-in-Chief. "It's an absolute mystery to me how intelligence does leak out. Now, what's to be done, Elphinhaye? What Q-boat does the message refer to?" "Q 171, sir," replied the secretary, never at a loss to supply the requisite information. "She was the old _Tollerdale_, and was adapted at Leith in January last." "Who's her commanding officer?" Elphinhaye had to consult a current Navy List. "Morpeth, sir. George Morpeth, an R.N.R. officer with the D.S.C." "By Gad! Morpeth! I knew him at Trecurnow," exclaimed the Admiral. "Smart fellow, but a bit of a rough diamond. I've no doubt that he can take care of himself, but all the same----" "We could wireless him, sir." "And warn every Fritz on this side of Germany," declared the Commander-in-Chief. "No, no, Elphinhaye. We must think of a better plan--one that, with luck, will entail a clean sweep of every Fritz who dares to poke his nose outside his kennel." Twenty minutes later the joyful signal was received by the Nth Light Cruiser Squadron and the Z Destroyer Flotilla:-- "Raise steam for thirty knots and prepare for immediate action on clearing harbour." CHAPTER XXIV IN THE HOUR OF HIS TRIUMPH "HAVE you any means of tracing the person who brought this message? inquired Entwistle. "Hardly," replied the Postal Censor's assistant. "One receives so many cables and telegrams for dispatch in the course of the day. I'll find out the name of the clerk on duty at the time, although I'm afraid the information will be disappointing." By means of a voice-tube, the official made various inquiries. "O'Donovon, is it?... Is he on duty now?... Just reported, eh? Good. Ask him to step up to my room, please." Presently a brisk tap on the door was followed by the appearance of a slight, rather pale-faced young man of pronounced Hibernian features. "This," said the Censor's assistant, "is 'Mr. O'Donovon. Mr. O'Donovon, this gentleman, Mr. Entwistle, wishes to ask you some information respecting a certain cablegram. Will you answer as fully as you can on the matter?" "I want you, Mr. O'Donovon," began Entwistle, "to give me a description of the person who handed in the message."