"This, I think," he continued, "covers all the evidence we have thus far collected in the Cab Mystery. It is quite satisfactory, as far as it goes, for it is circumstantial evidence, and, therefore, absolutely truthful. In the Knickerbocker Bank Mystery, we have as yet no satisfactory data whatever; for everything we have heard concerning it has its origin in the fallible evidence of witnesses, and has, moreover, reached us third or fourth hand. There is, however, one fact that may, or may not, prove to be important. Have you noticed that these two mysteries are contemporaneous, and, therefore, that they may be related?" "Do you think there is any connection between the two?" inquired Thurston, interested. "I do not allow myself to think about it at all as yet," replied Sturgis; "I simply note the fact, that, so far as time is concerned, the Cab Mystery could be the sequel to the Knickerbocker Bank Mystery--that is all. Facts, my dear boy, are like words. A word is only an assemblage of meaningless letters until it becomes pregnant with sense by context. So, a fact, which, standing by itself, has no meaning, may, when correlated with other facts, become fraught with deep significance." "And now," he continued, after a pause, "I think our work is concluded for the present. I shall be able to lay it aside for the night. Let me offer you a glass of sherry. Pleasant evening we spent at Sprague's to-night. I have a great admiration for him as an artist, and a great fondness for him as a man. Most of his friends are strangers to me, though. You know I have very little time to indulge in social dissipation. By the way, who is that Doctor Murdock with whom I have made this bet?" "Oh! he is a physician, though now retired from practice. He devotes himself entirely to scientific research, especially in the domain of chemistry. He has made some important discoveries in organic chemistry, and they say he has succeeded in proving some of the supposed elementary metals to be compounds. He has quite an enviable reputation in the scientific world. I understand he is a remarkable man." "That is evident at a glance. He showed himself this evening to be a clear thinker and a brilliant speaker. I should say he was something of a genius, and I should judge, moreover, that he was a man of magnificent nerve, capable of the most heroic actions, or----" Sturgis hesitated. "Or----?" asked Thurston. "Or of the most infamous cruelty and crime. It all depends upon whether or not his great mental attributes are under the control of a heart; a point upon which I am somewhat in doubt." CHAPTER VI. THE ARTIST.