"It's too bad. Will you please tell me what time it is?"

Andy McCabe glanced at the alarm clock that stood on the mantel-shelf.

"Quarter to six."

"As late as that!" cried Ferris. "I must hurry and catch him before six.
Only quarter of an hour. Good-day, sir."

"Good-day."

In a moment Ferris was gone. McCabe closed the door, and Hal came out of
the closet followed by Katie.

"What does he mean?" questioned the man.

"I'll tell you what it means," said Hal. "He is trying to prove an
alibi, in case a body was found in the vat. He thinks you can remember
he was here looking for Macklin at quarter to six. If that was true, how
could he have helped Macklin at five o'clock?"

"Well, well! he's a smart villain, so he is!" exclaimed Andy McCabe. "I
wonder what he would have done if you had stepped out of the closet?"

"I was strongly tempted to do that," laughed Hal. "But now I must be
off, Mr. McCabe. Please keep quiet, as I told you."

"I will, Mr. Carson. But where be you going?"

"To follow Ferris. Say, have you an old slouch hat you will exchange for
this cap of mine?"

"Here is one of Jack's."

"That will do first-rate."

Hal put on the hat and drew it down over his brow.

"Going to turn spy, be you?" remarked Andy McCabe.

"Yes."

"Well, I wish you luck."

Hal was soon out of the house. Once in the street, he looked up and
down.

Ferris was not in view, but he soon caught sight of the fellow coming
out of a tenement across the way. He crossed over and followed Ferris
toward Park Row, and then to the boarding house.

Here Hal heard the youth say something to his aunt about changing his
clothing, and the boy slipped into the house unobserved by anyone, and
did likewise. Ferris then left again, followed by Hal.

"I suppose he thinks he has laid good ground-work for his alibi,"
thought Hal. "Well, let him think so, he will be surprised before long
to learn the truth."

At Fourteenth Street Dick Ferris turned and walked toward Broadway. Hal
followed close behind, but in the crowd at the corner he lost track of
the fellow he was after.

He looked this way and that, and into the restaurants, but Ferris had
disappeared.

What was to do next? It was past supper-time, but Hal was in no humor
for eating.

Suddenly somebody brushed him rudely. It was a man wearing a heavy cape
coat. Hal glanced at the individual sharply, and was astonished to see
it was Mr. Caleb Allen.

Allen had not seen Hal