But that will come later. What we have to do now is to accompany him to the front of the building, where matters of importance undoubtedly await him. He had noted, in his previous passage to and fro, that the young man who had been nearest to the tragedy was in his place before the case of coins in Section I. This time he noted something more. The young man was in the selfsame spot, but during this brief interval of waiting, the passion he evidently cherished for numismatics had reasserted itself, and he now stood with his eyes bent as eagerly upon the display of coins over which he hung, as if no shaft of death had crossed the space without and no young body lay in piteous quiet beyond the separating partition. It was an exhibition of one of the most curious traits of human nature, and Mr. Gryce would undoubtedly have expended a few cynical thoughts upon it if, upon entering the broad front corridor which he had hitherto avoided, he had not run upon Sweetwater pointing in a meaning way toward two huge cases which, stacked with medieval arms, occupied one of the corners. "Odd couple over there," he whispered as the older detective paused to listen. "Been watching them for the last five minutes. They pretend to be looking at some old armor, but they are mighty uneasy and keep glancing up at the window overhead as if they would like to jump out." Mr. Gryce indulged in one of his characteristic exclamations. This was the couple whose queer actions he had noticed on the staircase. "I'll have a talk with them presently. Anyone in the rooms opposite?" "Yes, the Curator. He's in Room A, where there are a lot of engravings waiting to be hung. I guess he was pretty well up to his neck in business when that fellow Correy set up his shout. And have you noticed that he's a bit deaf, which is the reason, perhaps, why he was not sooner on the scene?" "No, I hadn't noticed. Anyone else at this end?" "Only the young couple I speak of." Mr. Gryce gave them a second look. They were by many paces farther from the pedestal from behind which the bow had been flung back of the tapestry than would quite fit in with the theory he had formed, and by means of which he hoped to single out the person who had sent the deadly arrow. But then, under the stress of fear, people can move very swiftly; and besides, what guarantee did he have that these poor, frightened creatures had located themselves with all the honesty the occasion demanded? According to Sweetwater there was nobody sufficiently near to notice where they had been at the critical instant, or where they were now. The student's back was toward them, and the Curator quite out of sight behind a close-shut door.