“I am afraid,” said Chick, as he followed his chief down the street indicated, “that we will find other streets that we will travel until daylight.” He had hardly gotten the words out of his mouth than he stopped short and dropped down on his knees, looking at something intently on the pavement. Nick halted, looking with great interest at what his aid was doing. He saw him take from his pocket a small lantern he always carried with him, and turn the light on a particular spot of the pavement. “What is it, Chick?” said Nick. “Red chalk marks,” said Chick. “Signs?” asked Nick. “Not our signs,” said Chick, “though they seem to look as if there had been an attempt to make one. But, chief, I’ll bet my life that this is the same chalk we use.” Nick bent down over the spot, and saw that the pavement was made of red brick; that it would have been difficult to have made one of the signs that they used between them, and that in this case the marks only seemed to have been hastily made without any form whatever. He stood up erect, looking at Chick. “Could those marks have been made by Ida?” asked Nick. “I am guessing that they were,” said Chick. “Anyhow, I gave Ida a piece of that chalk, and told her she ought to always carry it with her, for she could not know how useful it might become.” “Let’s look a little farther,” said Nick. “Wait a minute,” said Chick. “If any one comes, play drunk.” Backing up against a tree, Chick suddenly lifted that fine, manly voice his friends knew he had, in a popular song of the day, that rang out on the night air as clear as a bell. He had sung but a verse, when two men suddenly appeared at the corner beyond them, say a hundred feet away, and Nick began to urge him to come home and not make a holy show of himself in the street, saying that they’d have the cops down on them if he didn’t stop it. He could hear one man say to the other that it was only a couple of drunks, and saw them turn back and go out of sight. Chick sang another verse, and then both listened. There was an answer, indistinctly, yet clear enough for them to hear every note. They heard the third verse of the song sung through. “Ida’s here,” said Chick. “Are you sure?” asked Nick. “Sure!” replied Chick. “I’d know her way of singing in the wilds of Africa.” “Then you have found her,” said Nick. “And the next thing is to get to her.” On looking up, he saw nearly opposite where the marks on the pavement were, a door in the fence opposite to where they were standing. Both he and Chick carefully examined this door and the fence for further marks without finding any. Then Nick followed up the pavement, until he came opposite the door of the first house to be reached, and there beckoned to Chick, pointing with as much excitement as the great detective ever showed, to long red marks on the brickwork of the door. “That’s the house she is in,” said Chick.