I must admit that I was so delighted to find that Myra had recovered her sight that I very nearly made what might have been a very serious mistake. I gave a loud shout of triumph and made a dive for the light, intending to switch it on. This might, of course, have had a very bad effect upon my darling’s eyes, but fortunately Garnesk darted across the room and knocked up my arm in the nick of time.

“Not yet, Ewart, not yet,” he warned me. “We must run no risks until we are quite sure.”

“But, Ronnie, I can see quite well,” Myra declared delightedly. “I see everything just as easily as I usually can by the light of the dark-room lamp.”

“Still, we won’t expose you to the glare of white light just at present, Miss McLeod,” said Garnesk solemnly. “We must be very careful. Tell me, how did your sight return, gradually or suddenly?”

“Suddenly, I think,” the girl replied. “I took off the shade and laid it down, and then when I looked up I could distinctly see the lamp.”

“Immediately the shade was removed?”

“No,” she answered, “not just immediately. You see, I was looking at the floor, which is so dark, of course, that you couldn’t see it in the ordinary way. Then as soon as I looked up I could see the lamp. For a moment I thought it was my imagination, but when I found I could see Ron stooping over the developing-dish I knew that I was all right again.”

“This is very extraordinary, you know,” said Garnesk. “Can you count the bottles on the middle shelf?”

“Oh, yes!” laughed Myra, “I can make them out distinctly. Of course, I know pretty well what they are, but in any case I could easily describe them to you if I’d never seen them before.”

“What have I got in my hand?” the specialist queried, holding his arm out.

“A pair of nail-clippers,” Myra declared emphatically, and Garnesk laughed.

“Well,” he said, “you can obviously see it pretty well; but, as a matter of fact, it’s a cigar-cutter.”

“Oh! well, you see,” the girl explained airily, “I always put necessity before luxury!”

So then the oculist made her sit down again and questioned and cross-questioned her at considerable length.

“I’m puzzled, but delighted,” he admitted finally. “It’s strange, but it is at the same time decidedly hopeful.”

“I suppose it means that she will always be able to see in a red light at any rate?” I suggested.

“Probably it does,” he agreed, “and, of course, her sight may be completely restored. There is also a middle course; she may be able to see perfectly after a course of treatment in red light. I will get her a pair of red glasses made at once. We can see how that goes. But I feel that it would be advisable to introduce her to daylight in gradual stages, in case of any risk.”

“Oh, if we could only find poor old Sholto!” Myra exclaimed eagerly. Garnesk turned to her with a look of frank admiration.

“You’re a lucky young dog, Ewart,” he whispered to me, “by Jove you are!”

So Myra graciously, but a little regretfully I think, placed herself in the hands of the young specialist and replaced her shade. Then we left the dark-room, allowing the films to develop out on the floor, and went downstairs. We took her out on to the verandah and removed the shade for a moment, but the chill air of the highland night made her eyes smart after their unaccustomed imprisonment, and we gave up the experiment for that night.

As Garnesk and I bathed together in the morning we were both brighter and more cheerful than we had been since his arrival.

“I shall catch the train from Mallaig,” he declared. “Can you take me in and meet your friend without having long to wait?”

“If you insist on going,” I replied, “I can get you there in time to meet him and you will have an hour or more to wait for your train.”

“Oh, so much the better! We can tell him everything and give him all the news in the interval.”

“Are you still determined to go?” I asked.

“Yes,” he said, “I must go. It will be necessary for me to make one or two inquiries and get a pair of glasses made for Miss McLeod.”

“I shall be very sorry to lose you, Garnesk,” I said earnestly. “Don’t you think you could write or wire for the glasses? You see, if we have come to the conclusion that this green ray is some chemical production of Nature unassisted there isn’t the same reason for you to leave us.”

“No, that’s true,” he agreed, “but we were both a bit scared yesterday, old chap, and the more I think of this dog business the less I like it. It was mere conceit on my part that made me say it was bound to be some natural phenomenon merely because I couldn’t understand how the effect could have been humanly produced.”

“Perhaps,” I suggested, “our best course would be to keep an open mind about the whole thing.”

“Yes,” he replied, “I’m with you entirely. And in that case my going away is not going to aggravate the effects of a natural phenomenon, while it may restrain the human agency by removing the necessity for further activity.”

“Well, that’s sound enough,” I acquiesced; “but I shall hear from you, I hope?”

“Of course, my dear fellow,” he laughed, “we’re in this thing together. You’ll hear from me as often as you want, and who knows what else besides. I have no intention of dropping this for a minute, Ewart. But I think I can do more if I am not on the spot. We’re agreed that my presence here may be a source of danger to you all.”

“Yes,” I said, “I think yours is the best plan. What do you propose to do?”

“Well, to begin with, I shall devote an hour or two to knocking our panic theory on the head.”

“You mean the natural phenomenon idea?”

“Precisely,” said he. “I don’t think that it will be able to exist very long in the light of physical knowledge—not that that is a very powerful light, but it should be strong enough for our purpose. As soon as I have convinced myself that our enemy is a mere human being I shall take such steps as I may think necessary at the time. Then, of course, I shall acquaint you with the steps that I have taken, and we shall work together and round up our man, and, figuratively speaking, make him swallow his hideous green ray.”

“What sort of steps do you mean?” I asked.

“Well, that all depends,” my friend answered, “on what sort of man we have to deal with. But it will certainly include providing ourselves with the necessary means of self-defence, and may run to calling in the assistance of the authorities.”

“I’m not sure that the presence of the police in a quiet spot like this might not have a disastrous effect on our plans,” I pointed out.

“I shouldn’t worry about the police,” he laughed. “I should make for the naval chaps. I’m rather pally with them just now; I’m booked up to do some work of various descriptions for the period of the war, and I think if I can give them the promise of a little fun and excitement they would be willing to help.”

“Which indeed they could,” I agreed readily. “Any attempt our enemy might make to get away from us would probably mean a bolt for the open sea, and a few dozen dreadnoughts would be cheerful companionship.”

Garnesk laughed, and we strolled up to the house, putting the finishing touches to our toilet as we went. Shortly after breakfast we made ready for our trip to Mallaig. Myra was very anxious to come with us until I explained that we should have to wait there till we had met Dennis and seen the specialist off. She was naturally sensitive about appearing in public with the shade on, poor child, so she readily gave up the idea.

“I’m very sorry you’re going, Mr. Garnesk,” said Myra, as she shook hands.

“I shall see you again soon,” he replied. “I have by no means finished with your case, and as soon as you report the effect of the glasses I shall send you’ll see me come tripping in one afternoon, or else I shall ask you to come down to me.”

“It’s very good of you to take so much trouble about it,” said Myra gratefully.

“Not at all,” he responded lightly. “It is a pleasure, Miss McLeod, I assure you.”

The old general was still more effusive of his gratitude, and as he waved good-bye from the landing-stage his face was almost comically eloquent of regret.

“By the way,” said Garnesk as we passed Glasnabinnie, “don’t tell Hilderman much about what has happened. We feel we can trust him, but you never know a man’s propensity for talking until you know him very well.”

“Right,” I agreed. “I’ll take care of that. We can’t afford to get this talked about. It would be very painful for Myra and her father if it became the chatter of the country-side.”

“Besides,” Garnesk pointed out, “it will be much safer to be quiet about it. If we are dealing with men they will probably prove to be desperate men, and we don’t want to run any risks that we can avoid.”

“No,” said I, “this is going to be quite unpleasant enough without looking for trouble.”

So when we arrived in Mallaig and met Hilderman on the fish-table I was careful to remember my companion’s advice.

“Ah, Mr. Ewart!” the American exclaimed in surprise, “How are you? And you, Professor? I hope your visit has proved entirely satisfactory. How is Miss McLeod?”

“Just the same, I am sorry to say,” Garnesk replied glibly. “There is no sign at all of her sight returning. I can make nothing of it whatever.”

“Dear, dear, Professor!” Hilderman exclaimed, with a shake of the head. “That is very bad, very bad indeed. Haven’t you even any idea as to how the poor young lady lost her sight?”

“None whatever,” said Garnesk, with a hopeless little shrug. “I can’t imagine anything, and I’m not above admitting that I know nothing. There is no use my pretending I can do anything for poor Miss McLeod when I feel convinced that I can’t.”

“So you’ve given it up altogether, Mr. Garnesk?” Hilderman asked, as we strolled to the station.

“What else can I do?” the oculist replied. “I can’t stop up here for ever, much as I should prefer to stay until I had done something for my patient.”

“You have my sympathy, Mr. Ewart,” said Hilderman in a friendly voice. “It is a terrible blow for you all. I fervently hope that something may yet be done for the poor young lady.”

“I hope so too,” I answered, with a heavy sigh, but the sigh was merely a convincing response to the lead Garnesk had given me, for, as a matter of fact, I was quite certain that we had found the basis of complete cure.

“Yes,” Hilderman muttered, as if thinking aloud, “it is a very terrible and strange affair altogether. Have you had any news about the dog?”

“None whatever,” I replied, this time with perfect truth.

“Surely you must suspect somebody, though,” the American urged. “It is a very sparsely populated neighbourhood, you know.”

“We can’t actually suspect anybody, nevertheless,” said I. “On the one hand, it may have been an ordinary, uninteresting thief who stole the dog with a view to selling him again. On the other hand——”

“Well,” said Hilderman with interest, as I paused, “on the other hand?”

“It may have been someone who had other reasons for stealing him,” I concluded.

“I don’t quite follow you.”

“Ewart means,” said Garnesk, cutting in eagerly, evidently fearing that I was about to make some indiscreet disclosure of our suspicions, though I had not the slightest intention of doing so, “Ewart means that it may have been someone who regarded the dog as a personal enemy. Miss McLeod informs us that there was a man in the hills, ostensibly a crofter, who disliked Sholto, quite unreasonably. He drove the dog away from his croft and was very rude to Miss McLeod about it. She suspected an illicit still, and thought the fellow was afraid Sholto might nose out his secret and give the show away.”

“Ah!” said Hilderman. “An illicit still, eh! Where was this still, or, rather, where was the croft?”

I remembered that Myra had told us it was somewhere up Suardalan way, above Tor Beag, and I was just about to explain, when I felt my friend’s boot knock sharply against my ankle. Taking this as a hint and not an accident, I promptly lied.

“It was miles away,” I announced readily, “away up on The Saddle. Miss McLeod wanders pretty far afield with Sholto at times.”

“Indeed,” said the American, “I should think that might be quite a likely explanation, and rather a suitable place for a still, too. I climbed The Saddle some months ago with an enthusiastic friend of mine. We went by water to Invershiel, and then drove up the Glen. I shouldn’t like to walk from Invermalluch and back; there are several mountains in between, and surely there is no road.”

Evidently our shrewd companion suspected that I had either made a mistake or deliberately told him an untruth, but I was quite ready for him. I had no time to consider the ethics of the matter. I was out to obey what I took to be my instructions, and obey them I did.

“Oh, there are quite a lot of ways of getting there,” I replied airily; “but perhaps the easiest would be to take the motor-boat to Corran and walk up the Arnisdale, or follow the road to Corran and then up the river. Miss McLeod has her own ways of getting about this country, though, and she may even know some way of avoiding the difficulties of the Sgriol and the other intervening mountains.”

Hilderman looked at me in considerable surprise for a moment.

“You seem to know the district pretty well yourself, Mr. Ewart,” he remarked.

“Well, I ought to,” I explained; “I was born in Glenmore.”

“Oh, I didn’t know that,” he murmured; “that accounts for it, then.” And at that moment we heard the train approaching, and we hurried into the station to meet our respective visitors.

“Fact or fancy?” asked Garnesk in an undertone as we strolled down the platform, Hilderman having hurried on ahead.

“Fancy,” I replied. “I took it you wanted me to avoid giving him the precise details.”

“Yes, I did,” he laughed. “But you certainly made them precise enough. It is better to be careful how you explain these things to strangers.”

“Why?” I asked. “If we suspected Hilderman I should be inclined to agree with you that we should feed him up with lies; and if you think it will help us at all to suspect him I’m on at once. But as we both feel that his disposition is friendly and that we have no cause to doubt him, what is your reason for putting him off the scent every time? I know you well enough by this time to feel sure that you haven’t been making these cryptic remarks for the sake of hearing yourself speak.”

“Here’s the train,” he said. “I’ll tell you later.”

I looked along the carriages for Dennis, but I had evidently missed him, for as I turned back along the platform I found him looking round for me, standing amid the mÊlÉe of tourists and fisherfolk, keepers and valets, sportsmen and dogs, which is typical of the West Highland terminus in early August, and which seemed little affected by the fact that a state of war existed between Great Britain and the only nation in the world which was prepared for hostilities.

“Well, old man,” I greeted him as we shook hands heartily. “You got my wire, of course. I hope you had a decent journey.”

“Rather, old chap, I should think I did!” he replied warmly. “Slept like a turnip through the beastly parts, and woke up for the bit from Dumbarton on. I also had the luck to remember what you said about the breakfast and took the precaution of wiring for it. Here I am, and as fit as a fiddle.”

“That’s great!” I exclaimed cheerily, for Dennis’s bright attitude had exactly the effect on me that it was intended to have—it made me feel about twenty years younger. “This is Mr. Garnesk, the specialist, who very kindly came from Glasgow to see Myra. Mr. Garnesk—Mr. Burnham.”

The two shook hands, and the oculist suggested lunch. We left the station to go up to the hotel, but we saw Hilderman and his newly arrived friend—the same man who had seen me taking Myra up to London—walking leisurely up the hill in front of us. Garnesk took my arm.

“Steady, my boy, steady,” he said quietly. “We don’t want to be overheard giving the lie to your dainty conversation of a few minutes ago. Isn’t there anywhere else we can lunch, because they are evidently on the same tack?”

“Yes,” I replied, turning back, “there’s the Marine just behind you. That’ll do us well. Then we can come out and talk freely where there’s no chance of our being overheard.”

So we lunched at the Marine Hotel, after which we strolled round the harbour, along the most appalling “road” in the history of civilisation, popularly and well named “the Kyber.” Safely out of earshot, I made a hurried mental prÉcis of the events of the past few days, and gave Dennis the resultant summary as tersely as I could.

“I’m very glad you had Mr. Garnesk with you,” said Dennis at last, with a glance of frank admiration at the young specialist.

“Not so glad as I am,” I replied fervently. “What I should have done without him heaven only knows. I can’t even guess.”

“Oh, nonsense!” cried Garnesk, in modest protest. “I haven’t been able to do anything. Our one advance was a piece of pure luck—the discovery that Miss McLeod could see by the light of a red lamp. We have decided to keep that quite to ourselves, Mr. Burnham.”

“Of course,” agreed Dennis, so emphatically that I laughed.

“Why so decided, Den?” I asked, for I felt that I should like to climb to the topmost pinnacle of the highest peak in all the world and shout the good news to the four corners of the earth.

“I’m not a scientist, Ron,” Dennis replied. “That may account for the heresy of my profound disbelief in science. I wouldn’t cross the road to see a ‘miracle.’ The twentieth century is uncongenial to anything of that sort. Take it from me, old chap, there’s a man at the back of this—not a nice man, I admit, but an ordinary human being to all outward appearances—and when we catch a glimpse of his outward appearances we shall know what to do.”

“Yes, when we do,” I sighed.

“You mustn’t let Ewart get depressed about things, Mr. Burnham. He very naturally looks at this business from a different standpoint. With him it is a tragic, mysterious horror, which threatens the well-being, if not the existence, of a life that is dearer to him than his own.”

“I’ll look after him,” said Dennis, with a grim determination which made even Garnesk laugh.

“When you two precious people have finished nursing me,” I said, “I hope you’ll allow me to point out that that very reason gives me a prior claim to take any risks or run into any dangers that may crop up from now on. If there is any trouble brewing, particularly dangerous trouble, then it is my place to tackle it. I am deeply grateful to you fellows for all you have done and are doing and intend to do, but the nursing comes from the other side. I can’t let you run risks in a cause which is more mine in the nature of things than yours.”

“I fancy,” said Dennis, “that even your eloquent speeches will have very little effect when it comes to real trouble. If danger comes it’ll come suddenly, and we shall be best helping our common cause by looking after ourselves.”

“Hear, hear,” said Garnesk, and I could only mutter my thanks and my gratitude for the possession of two staunch friends.

“To get back to business,” I said presently, “why did you want me to bluff Hilderman like that?”

“Because,” said Garnesk slowly, “I’m not sure that Hilderman is the man to take into our confidence too completely. It’s not that I don’t trust the man, but he looks so alert and so cute, and has such a dreamy way of pretending he isn’t listening to you when you know jolly well that he is, that I have a feeling we ought to be careful with him.”

“Very much what Dennis said about him the first time he saw him. But if you don’t suspect him, and he is a very cute man, why not trust him and have the benefit of his intelligence?”

“How would you answer that question yourself, Ewart?” the specialist asked quietly.

“Oh,” I laughed, “I should point out that his cuteness may be the very reason that we don’t suspect him.”

“Precisely,” Garnesk agreed; “and that is partly my answer as well.”

“And the other part?” put in Dennis quietly.

“Well, it’s a difficult thing to say, and it’s all conjecture. But I have a feeling that Hilderman is not what he says he is. He has a knack of doing things, a way of going about here, that gives me the impression he is employing his intelligence, and a very fine intelligence it probably is, all the time. I don’t think he is retired at all. There’s a restless energy about the fellow that would turn into a sour discontent if his mind were not fully occupied with work which it is accustomed to, and probably enjoys doing.”

“Have you anything to suggest?” I asked.

“I have an idea,” he replied; “but I haven’t mentioned it because it doesn’t satisfy me at all. I have an idea that the man is some sort of detective hard at work all the time. But I can’t imagine what sort of detective would take a house up here and keep himself as busy as Hilderman appears to be over some case in the neighbourhood. I can’t imagine what sort of case it can be.”

“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.