There was something so weird and so unreal in the sound of his own name, coming to the detective as it did, seemingly from the infinity above him, that for a moment he quite refused to believe that his ears had not deceived him.

Remember, there was the thundering of the waves against the rocks all around him; the boom of the surf as it broke beneath its own weight and violence farther out toward the sea; the sobbing and moaning of the wind over the bleak cliff and through the ruins of the older part of the castle, and the faint cries of sea-birds coming to him from far away to windward. All this tended to render him uncertain about the voice which seemed to call to him from the black sky over his head; just as all this made it impossible to determine whether the voice, if it were indeed a voice, had proceeded from a man or a woman.

But sober second thought reassured him.

Who, but one person in all the world, could have called to him there?

He knew that it was impossible, even if Bessie Harlan were indeed a prisoner inside the old château, that she should have witnessed his approach, or that she should have recognized him from her aerie window, even if she had discovered the approach of two pedestrians before[185] the gathering darkness had hidden them from view. But he explained the seemingly inexplicable phenomenon in quite another way than that.

“If Bessie is a prisoner there,” he reasoned to himself, “she believes absolutely that Max and I will come to her rescue, sooner or later. If she is a prisoner there, she is confined in a room which overlooks the sea—a room in this very tower, in fact; and if all that be true, that call of hers was simply a wail of impatient waiting and longing, called out by her to the heavens, the clouds, the sea, the wide, wide world. Not in the hope that it would literally be heard, perhaps, but, nevertheless, a call to us to hasten.”

Several moments he waited, wondering if there would be a repetition of the call; and then, when one came, he wondered again if he should reply to it. His better judgment told him not to do so, and so presently he turned away to pursue his course around the castle.

But he discovered, presently, that he had been deceived in his surmises that it would be possible for him to skirt the tower between it and the water, and, at last, satisfied that he could not do so, he turned back again over the course he had come.

He was not long in arriving at the spot where he had left Kane, but he did not pause there. After hesitating just one instant in order to get his bearings properly, he started forward again toward the place where they had agreed to meet.

When he arrived there, however, Maxwell Kane was not there, and the detective could discover no trace of him[186] in any direction. He waited a few moments, thinking that something might have detained him, and that he had, therefore, not yet arrived, although he knew all the time that nothing of an ordinary nature could have done so.

There were no impediments in the way between the spot where they had parted and where they agreed to meet.

Nick had just traversed every inch of it, and he had met with no obstacle of any kind, nor had he seen a sign of life or a light anywhere.

For that very reason he figured that doubtless something had attracted the attention of Kane after his arrival at the place of meeting, and he had gone to investigate. But after he had waited fully half an hour, the detective decided that it was time for him to move.

He had not a doubt now that something had happened to his companion. He was confident, however, that Kane could not have fallen, or have met with an accident, without the intervention of another person.

Presently he scribbled these five words: “Wait here till I return,” on a leaf torn from his book of memoranda, and, wrapping it in a handkerchief, he weighted it with a pebble and left it where the white of the cambric would attract the attention of Kane, should he regain the spot before the detective could get back again.

“And now to break my way into that castle,” he mused. “And I must take extra care, too, for if some prowlers around this old pile have captured Kane, they will be on the lookout for me as well.”

The low building, which resembled a bowling-alley[187] more than anything else, and which extended from one wing of the castle to the edge of the bluff on the side toward the harbor, had evidently been erected originally to serve as a passageway between the château and the water when the weather was inclement; and this was the building which was before him now. But in inspecting it from a distance the detective had decided that this would provide a means of entrance. It was almost windowless, and such as it contained were much too small and too high from the ground to serve his purposes.

He therefore turned again toward the castle, and hurried toward a spot where he remembered to have seen a wealth of ivy growing against the old walls. He had not forgotten their locality, and he went directly to the spot.

The ivy was old and tough, and had grown firmly in its place, so that when he placed his hands upon it he knew that it would sustain him readily. He recalled the fact that the ivy trailed across several windows, and so he began at once to make his way up it.

The dampness of the falling rain had rendered the ivy in such a condition that it gave out no sound as he climbed, while the dark background against which he clung afforded no opportunity for prying eyes to discover him.

He climbed rapidly, for he realized now that haste was necessary. The strange call to him from the window of the tower, and the disappearance of Maxwell Kane, had convinced him that all was not to be as smooth sailing as he had anticipated.

Soon he arrived at a window, set deeply into the wall,[188] and casemented for defense in time of attack. But this window had long been in disuse, and even the glass had been replaced by heavy planking, to keep out the wind and weather.

There were two more stori............