Suddenly there sounded on the air the sharp, yelping bark of a frightened dog, ending in a prolonged howl.
Patsy slipped back to the pavement and to the cover of some boxes that were piled nearby.
The two waited but a moment, when Chick came down the street, looking in every direction.
Nick gave a low signal, and Chick darted into the hallway where Nick was, Patsy quickly joining him.
CHAPTER XIII.
A DESPERATE STRUGGLE.
“I have been following Lannigan and the unknown all night,” said Chick.
“What have they been doing?” asked Nick.
“Something that they have regarded as important, but what I am not certain.”
He rapidly told his experiences of the night, the important feature of which, to Nick, was Lannigan’s visit to Rivington Street, and his entrance to a house there with the unknown, his long stay, and, finally, the hurried departure of the unknown and his running up to Fourth Street for the coach, which was brought down to Rivington Street.
It was there that Chick had sneaked up behind it and tied the yellow cloth to the hind axle, on the chance that Patsy or Nick, or both, might see it, and know that it was one followed by Chick.