"What about a secret German naval base in the Hebrides?" I suggested. "It's not by any means impossible or even unlikely that the Germans have utilised the lonely lochs and creeks to some sinister purpose. Many of the lochs are entirely hidden by surrounding mountains, which come right down to the edge of a narrow opening, and make the place almost unnoticeable unless you happen to be looking for it." "There's something in that, certainly," Garnesk agreed; "but we must remember he's been here since May. Surely our precious Government would have managed to find what they wanted, and clear it out by this time. Then again, did they suspect the base, or did they have a general idea that war was coming so far back as May?" "As to the war," Dennis put in, "we don't really know when the authorities had their first suspicions." "No," said I; "but I fancy it was not a very definite suspicion until after the Archduke was assassinated. But look here, Garnesk, just let us suppose Hilderman really is a Government detective in the guise of an American visitor. Wouldn't he be just about the man we want, or do you think it would make too much stir to take him into our confidence?" "Far too much," Garnesk replied emphatically. "It's not that he would talk; but if he has been here all this time his opponents have got wind of him long before this, and his arrival on the scene in connection with our case would give any suspicious character the tip to bolt. I should advise keeping in touch with Hilderman, learn as much as you can about him, and be ready to run to him for help if you come to the conclusion that he is the man to give it." We sat down among the heather at the foot of the Mallaig Vec road, and looked out over the harbour. "Don't turn your heads," said Dennis quietly, "but glance down at the pier." "Yes," said Garnesk in a moment, "he seems to be as interested in us as we are in him." Hilderman and his friend were standing on the end of the pier watching us through their field-glasses. CHAPTER XIII. THE RED-HAIRED MAN. "I'll send the glasses at once," said Garnesk, as the train steamed out of the station. Dennis and I stood on the platform and watched him out of sight. "He seems a good fellow," said Dennis. "Splendid!" I agreed readily. "He's exceeding clever and wide-awake, and very charming. What we should have done without him heaven only knows. I fancy his visit saved the entire household from a nervous collapse." "We've no time for collapses, nervous or otherwise," Dennis replied. "We shall want our wits about us, and we shall need all the vitality we can muster. But at the same time I don't think there is any cause for nerves. You're not the sort of man, Ron, to let your nerves get the better of you in an emergency, especially if we can prove that our enemy is a tangible quantity, and not a conglomeration of waves and vibrations." "Hilderman and his friend appear to be waiting for us," I interrupted.