"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?"