And, meanwhile, Helga Lund would not know what real peace of mind was until she was informed that her vindictive persecutor had been captured. Three days was spent in this fruitless tracking, and then, in the absence of tangible clews, the great detective turned to something which had often met with surprising success in the past. He banished everything else from his mind and tried to put himself, in imagination, in Doctor Grantley’s place. What would this brilliant, erratic, but misguided genius, with all of his unbridled enmities and his criminal propensities, have done that night, after having escaped from prison and brought Helga Lund’s performance to such an untimely and harrowing close? It was clear that much depended on the depth of his hatred for the actress who had repulsed him five years before. Undoubtedly his enmity for the beautiful Swede was great, else he would not have timed his escape as he had done, or put the first hours of his liberty to such a use. But would he have been content with what he had done that first night? If he had considered his end accomplished, he might have shaken the dust of New York from his feet at once. On the other hand, if his thirst for revenge had not yet been slaked, it was probable that he was still lurking near, ready to follow up his first blow with others. The more Nick thought about it the more certain he became that the latter supposition was nearer the truth than the former. Grantley had caused Helga Lund to break down completely before one of the most important and critical audiences that had ever been assembled in New York, to be sure, but, with a man of his type, was that likely to be anything more than the first step? He had threatened to ruin her career, and he was nothing if not thorough in whatever he attempted. Therefore--so Nick reasoned--further trouble might be looked for in that quarter. The thought was an unwelcome one. The detective had taken every practicable precaution to shield Helga from further molestation, but he knew only too well that Grantley’s attacks were of a sort which usually defied ordinary safeguards. The possibility of new danger to the actress spurred Nick on to added concentration. Assuming that Grantley was still in New York, in disguise, and bent upon inflicting additional injury on the woman he had once loved, where would he be likely to hide himself, and what would be the probable nature of his next move? The detective answered his last question first, after much weighing of possibilities. Grantley was one of the most dangerous of criminals, simply because his methods were about as far removed as possible from the ordinary methods of criminals. He had confined himself, thus far, to crimes in which he had made use of his immense scientific knowledge, surgical and hypnotic.