van dusen hurried to the marion address, where he found ethel's maid thoroughly enjoying the vacation that had resulted for her from doctor garnet's action. using his alias of jack scott, van dusen explained to the girl the situation that had developed, which was so perilous to her young mistress. when the maid had recovered from her first dismay, she told freely all that she knew, and this was sufficient easily to give van dusen the suspicion that the family physician might be in fact the guilty man, who was responsible for ethel's disappearance.

the detective's next visit was to the office of doctor garnet. there he found the physician's secretary much worried over the prolonged and unexplained absence of his employer. he declared that the last time he had seen doctor garnet was several days before when he had left in answer to a hurry call from the victim of an accident. the secretary added that he had made careful inquiries in every possible direction, but had been unable to find any trace whatsoever of the missing man.

van dusen gave only vague answers to the anxious questions put by the secretary. he stated merely that a client of his was anxious to get in touch with the physician. then, without more ado, he hastened to keep his appointment with roy. his own face, now he was alone without any necessity for the mask of indifference, was deeply perturbed. consternation was written in his expression. his deductions brought him face to face with the fact that garnet was actively concerned in the mystery. either the physician was actually guilty of abducting his girl patient for some evil purpose of his own, or else he himself was also a victim of the kidnappers along with ethel. or, finally, the man had suddenly become deranged from nerve strain and overwork, and in this irresponsible condition had stolen away the girl, with what crazy design none might guess. this possibility was even more dreadful than the others since there could be no certainty as to what the madman might intend. van dusen realized, with a shudder of horror, that in haste must lie the only chance of rescuing the girl from some horrible fate. it seemed to him that the single feasible plan would be to follow down the coast according to the directions given in ethel's letter to roy. while doing this the wireless on his yacht would keep constantly in touch with all southern ports and with the coastwise steamers for news of the isabel. then whenever the stolen yacht should be located, if fortune so favored, it would be pursued with all speed in the hope of effecting a rescue.

van dusen found roy pacing uneasily to and fro in an outer room at the agency. he had performed the duties entrusted to him by the detective and was now wild with impatience for further action. his first glance into van dusen's face stirred him to new excitement.

"oh, arthur!" he exclaimed, "i can see by your expression that you have obtained important information. tell me!" he insisted. "tell me! i must know—even if it's the worst. in these hours of suspense and despair, i've braced myself to stand any shock. tell me!"

van dusen answered soothingly.

"roy, old man, the mystery will be solved, i think, and that before long. that is to say, it will be cleared up unless the isabel founders at sea before we can reach it. i have discovered that in all human probability miss marion has been carried away in the yacht by doctor garnet."

"are you positive about that?" roy demanded fiercely.

"i am positive this far," came the quiet reply. "doctor garnet has not returned to his office since the time when he answered the call to attend miss marion on the yacht. it is fairly to be deduced from her message to you that he appeared on board in answer to her summons. i am of the opinion that doctor garnet is the one responsible for this outrage. he is either the victim of a sudden fit of insanity, or he has become a man-beast, sacrificing position and honor and every decent instinct in order to gratify a heretofore smoldering lust, which has suddenly flamed forth and got beyond his control."

"your deductings are doubtless right—at least in part," roy admitted, though with obvious reluctance in his tone. "but i find it hard to believe the possibility of doctor garnet's being the brute you suggest. he is universally esteemed not only for his ability, but also for his manliness and his many deeds of kindness and charity. if he has done this thing it must have been as you also suggest because he has gone crazy."

roy mused for a moment, and then spoke with a new note of excitement in his voice.

"how do we know that the doctor was not murdered while on board the yacht, and that the murderer or murderers then made off with the vessel and marion? or, perhaps, the tender was capsized and he was drowned along with the caretaker. afterward the kidnapping may have been done by others who knew nothing whatever of doctor garnet." roy shook his head with decision. "anyhow," he added, "i cannot believe that doctor garnet, in his right mind, could ever have been guilty of such a foul crime."

van dusen regarded the young man tolerantly, but his smile was a little cynical as he replied:

"when you have studied crime as thoroughly as i have during the past few years, roy, you will not be so confident of finding nothing but good in any particular man, no matter how high his reputation may be. i cannot say with certainty that doctor garnet is vile; neither can i say that he is incapable of vileness. but in the work i have to do, i must entertain all possibilities if i would solve the problem."

"well, arthur," came roy's reply after a moment of reflection, "i admit that i am amazed by what you have told me. i do not in the least understand the turn of affairs by which doctor garnet is implicated. but you are in charge of the case, and i am absolutely in your hands. i mean not to hamper you in any way—not even by throwing doubts on your judgment. so, now, just tell me what you mean to do next."

van dusen answered authoritatively:

"we must leave at once. on my way here, i sent out wires to norfolk and other near-by coast points. these will be sufficient to keep the port officers on the lookout for the isabel, as well as the coast-guard crews. i have a wardrobe on board my yacht. whatever you may need beyond what's in your bag, i can supply you with. let's be off."

van dusen's yacht was moored near the spot where the isabel had been lying. the detective made diligent inquiry at the landing stage in the hope of picking up some bit of information concerning doctor garnet's presence there, but the effort was fruitless. no one seemed to have known anything concerning the physician's visit.

forthwith, then, the two young men went aboard van dusen's yacht, and a few minutes later the vessel was under way, with instructions to the master to hug the new jersey shore while keeping a sharp lookout for the isabel.

the detective operated his own wireless outfit and for several hours at the outset of the voyage he kept busy, interrogating the different ships bound up and down the coast, and the shore stations as well, for any information concerning the stolen yacht. finally, a tramp steamer answered that she had passed the isabel the day before, and that the yacht at that time was headed down the coast, going slowly, in the direction of hampton roads. at once, on receiving this news, van dusen directed that the yacht's course should be set for cape charles and the roads.

as a matter of fact, without this information, the yacht must have taken this same direction for the sake of safety, since the weather soon became so threatening that none but the most foolhardy would have ventured to navigate in the open sea a vessel of the hialdo type.

the hialdo pushed her nose through the waters of hampton roads in the early morning. both roy and van dusen were on the bridge, surveying with their glasses every detail visible of the bays and creeks. they dared hope to catch somewhere a glimpse of the isabel, for they believed that she must be secreted somewhere hereabouts in some out-of-the-way place. they were justified in this by the fact that they had received no word of the yacht's arrival from the harbor authorities of norfolk. yet, now, their roving scrutiny was of no avail. nowhere could they find a trace of aught that could possibly be mistaken for the isabel.... with the approach of night the violence of the gale became such that perforce van dusen gave orders for the tying up of the the hialdo at the norfolk port, there to await the passing of this southeaster of hurricane force.

the hours during which the tempest raged were fraught with horror for roy morton. he was in despair now, for he could not believe that the isabel would be able to ride out the gale. his imagination pictured for him with frightful vividness the wreck of the yacht and its carrying down to death the girl he loved. the young man's agony of spirit was so evident that van dusen became alarmed lest he should break down. the detective thought to distract roy from his morbid thoughts by suggesting that they take a trip into the town to lessen the tedium of waiting until the storm should wear itself out. his persistence at last won a reluctant consent, and the two set forth.... in after years, roy was to think often with shuddering of what must have been the dreadful result, had he indeed refused to accompany the detective on that excursion into the town.