But Morlandson had died, burnt to death in his laboratory within a year or so of his release. How was this fact to be fitted in with this theory? The Black Sailor had enlightened him upon this point. Dr. Morlandson had handed on his vengeance to this mysterious successor, whose true identity he had no means of guessing. It was true that in one direction his doubts had been resolved, but only to be replaced by a series of questions, equally imperative. Who was this man, who called himself the Black Sailor? The Professor had examined his appearance intently while the light lasted, and could see none of the obvious traces of disguise. He could swear that his most striking beard and whiskers had been genuine, and he had worn his clothes naturally, as though accustomed to them. Again, how had he known that Dr. Priestley was in the neighbourhood? The Professor was certain that he had not been followed during his journey from London. It was impossible that this man should live openly, with the reward for the Black Sailor circulating all over the country. Was it possible that he lived concealed somewhere in this desolate tract of country? And if so, how did he contrive to carry out his murders within the very heart of London? These problems would wait. A more urgent one seemed to the Professor to require solution. What, he asked himself, had the Black Sailor’s object been in seeking this meeting? The Professor was quite prepared to believe that the reason he had given accounted for part of the truth. He could well imagine Morlandson, his brain turned by his fancied grievance, wishing the effects of his vengeance to become known. This was to be expected, it was merely an example of the curious vanity usually displayed by maniacs. But was there any other purpose in the meeting, which he had not yet understood? And, in any case, what course was he to take? As the Black Sailor had suggested, to set the local police on the scent would be sheer waste of time. No serious attempt to scour the heath could possibly be made before daylight next morning, by which the object of the search would be far away. They might find the tracks of his bicycle, but if he desired to elude pursuit all he would need would be to carry it for some distance over the heather. The Professor credited the man who had baffled the London police by the ingenuity of his murders with sufficient acumen to leave no tracks by which he could be followed. No, the police could not help him, if he were to escape the fate that threatened him, it must be by his own efforts.