CHAPTER I.
A DOUBLE MURDER.

“Hello! hello! This is Frank Mantell talking. I want Mr. Carter—Nick Carter. Is he there?”

Patsy Garvan, the detective’s junior assistant, then alone in the library of Nick’s Madison Avenue residence, was the recipient of the above telephone communication. It came over the wire in tones reflecting the haste and excitement of the speaker.

Patsy remembered him, a son of the senior partner of the firm of Mantell& Goulard, whose big department store in Sixth Avenue had recently been wrecked by a long series of mysterious robberies committed by the junior partner, Gaston Goulard, resulting in a round-up of the criminal and his confederates by Nick and his assistants, all of which had transpired several months before.

“No,” Patsy replied. “Nick Carter is not here. He is out on a case.”

“Is Chick Carter there?” Mantell then hurriedly asked, referring to the detective’s chief assistant.

“He is not, Mr. Mantell. This is Garvan talking.”

“Ah, yes, Patsy—I remember,” was the reply. “When will Nick return?”

“I don’t know. He went with Chick about an hour ago to investigate a big murder case in Manhattanville. He may not return until evening.”

“Dear me, I’m sorry to hear that. I am very anxious to see him.”

“On business?”

“Yes. Very important business. There is half a million dollars involved.”

“Great Scott! Can I be of any help to you?”

“Not unless you can enable me to see Nick himself. Time is very valuable.”

“I can do that, perhaps,” said Patsy. “I can learn from police headquarters just where he has gone. You can go there and see him, or—where are you phoning from, Mr. Mantell?”

“From the office of Gray’s wharf, East River. I cannot explain by telephone. If——”

“One moment,” Patsy interrupted. “Have you a taxi?”

“I have my touring car.”

“Good enough! Join me here as quickly as possible. I’ll find out in the meantime where Nick is engaged. We’ll go there and see him.”

“Thanks, Garvan, a thousand times. I’ll be with you in ten minutes.”

It then was about ten o’clock in the morning. One hour earlier, complying with an urgent telephone request from the police headquarters, Nick Carter and Chick arrived in the detective’s touring car at a dwelling in one of the outskirts of Manhattanville, the scene of a shocking crime evidently committed the previous night.

It was an attractive wooden house somewhat back from the street and occupying a corner lot.

It was in a quiet and entirely reputa