At last, as Dunlap reached the Knickerbocker bank, the clock in the belfry struck the hour. The reporter was not there. The banker uttered an ejaculation of annoyance. He looked up and down the street. There was no one in sight. He resolved to give Sturgis five minutes grace, and began to pace back and forth before the entrance to the bank. Then a thought struck him. There was another entrance on Exchange Place--that generally used by the employés and officials. Perhaps the reporter was waiting there. Dunlap walked around to Exchange Place and glanced up the street. He saw a man standing in the gutter and bending low over the curb. Dunlap advanced so as to obtain a front view of him and recognized Sturgis. The reporter had not noticed his approach; he held a magnifying glass in his hand and seemed deeply interested in a minute examination of the smooth-worn curb. "Good morning, Mr. Sturgis," said the banker, "have you lost something?" The reporter looked up quietly. "No, Mr. Dunlap; I have found something;--something which may possibly prove to be a hyphen." "A what?" asked the banker, perplexed. "A hyphen connecting two parts of a very pretty little puzzle." Dunlap stared curiously at the curb. "I can see nothing there," said he. Sturgis handed him the magnifying glass. "Now look again." He pointed out a particular portion of the curb. Dunlap looked in the direction indicated. "I see what looks like dried mud, dust particles, and a little dark spot or stain." "Yes," said Sturgis, "that dark spot is the hyphen. There were probably others like it on the sidewalk yesterday afternoon, but they have been obliterated by the pedestrians. Here, however, are some that have remained." As he spoke, he led Dunlap to the Exchange Place entrance of the bank, and pointed out a number of similar spots on the stone steps. "Fortunately," he said, as if speaking to himself, "fortunately the detectives entered through the front door last night; so that they did not interfere with this portion of the trail." "But what are these spots?" asked the banker. "They are blood-stains," replied the reporter. "I have every reason to believe them to be human blood. But that question I can settle positively as soon as we are in the bank, for I have brought a powerful microscope. Let us enter now, if you like; I have seen all there is to be seen outside. By the way, do you know this key?" He held up a large steel key of complicated structure. "Why," exclaimed Dunlap surprised, "that looks like the key to the Exchange Place door. Where did you find it?" "In the gutter, near the sewer opening at the corner." "But how did it get there?" asked Dunlap anxiously. "Perhaps I shall be able to answer that question presently," said Sturgis. "Shall we go in now? No, not that way. Let us enter by the Wall Street side, if you please." A couple of minutes later, the outer door of the Knickerbocker bank was unlocked.