“Yes; you’re right. Well, at any rate, he must have been sitting here, opposite Mr. Gately, on that very day. And I opine he was telephoning, but that makes no difference. Now, if he was here, in this office, on that day,—what was he here for, and who is he?”

“He is the murderer,” said Zizi, but she spoke as if she were a machine. The words seemed to come from her lips without her own volition; her voice was wooden, mechanical, and her eyes had a far-away, vacant gaze. “I don’t know who he is, but he is the man who shot Mr. Gately.”

“Oh, come, now, Ziz,” Wise shook her gently, “wake up! Don’t jump at conclusions. He may be the most innocent man in New York. He may have been in here calling on Gately early in the day, and his errand may have been of the most casual sort. He may have had cause to telephone, and as he sat waiting for his call, he sketched the snowflake pattern, which is his habit when waiting. But that he was here that day is a positive fact,—to my mind. Now, it’s for us to find out what he was here for, and who he is. I don’t favor going to him and asking him pointblank. That peculiar phase of amnesia from which he is suffering is a precarious matter to deal with. A sudden shock might bring back his memory,—or, it might——”

“Addle his brain!” completed Zizi. “All right, oh, Most Wise Guy! But when you do find out the truth, it will be that Case Rivers in his right mind and in his own proper person killed Mr. Gately.”

“Hush up, Ziz! If you have such a fearful hunch keep it to yourself. I’m not going to believe that, unless I have to! It has always been my conviction that Rivers is,—or was, a worthwhile man. I feel sure he was of importance in some line,—some big line. Moreover, I believe his yarn about falling through the earth.”

“You do!” I cried, in amazement. “You stand for that! You believe he fell into the globe at Canada,—or some Northern country, and fell out again in New York City?”

“Not quite that,” and Wise smiled. “But I believe he had some mighty strange experience, of which his tale is a pretty fair description, if not entirely the literal truth.”

“Such as?”

“Why, suppose he fell down a mine shaft in Canada. Suppose that knocked out his memory. Then suppose he was rescued and sent to New York for treatment, say, at some private hospital or sanitarium. Then suppose he escaped, and, still loony, threw himself into the East River—oh, I don’t know—only, there are lots of ways that he could have that notion about his fall through the earth, and have something real to base it on.”

“Gammon and spinach!” I remarked, my patience exhausted; “the man had a blow or a fall or something that jarred his memory, but his ‘falling through the earth’ idea is a hallucination, pure and simple. However, that doesn’t matter. Now we must follow this new trail, and see if we can get a line on his personality. He can’t tell us what he was here for,—if he doesn’t remember that he was here.”