“But haven’t you traced him?”

“Traced him, nothing. He’s simply vanished into thin air. And, believe me, it’s no cinch for one of our men to disappear without our tracing him pretty quick. No, this gang is no slouch, I’ll say that for it.”

As I learned later on, a descent into slang was a sign of considerable feeling on the part of the Chief. But at this time his attitude struck me as a little unfeeling.

“Well,” I said, “it looks to me as if you were up against something pretty difficult. But do you mean that I can really be of some assistance to you in the business?”

“That’s it exactly. For this type of work, with this type of people, don’t you see that we’ve got to have operatives who have the social entry if we’re to get anywhere? Moore’s all right. But he can’t do it all alone. And besides, he won’t last long alone, probably, as you saw for yourself. Now if you join us in this work, you’ll be looking for your sister with the whole power of the Department back of you. But we want you to find her and bust up the gang, as much as you do yourself. There’s the situation. You’re fitted for the work, you’re vitally interested, and we can help each other. Afterwards, we’ll release you as soon as you like, if——” He left the sentence unfinished.

“If there’s anything left to release,” I added dryly.

“You’ve hit it exactly,” he smiled.

It did not take me long to make up my mind. I had nothing to lose and possibly everything to gain by joining the Department, if they were willing for me to continue my search in my own way. And working with the consciousness of a powerful organization back of me was infinitely preferable to doing it alone. I had expected that they might want me to work entirely under their direction, possibly in remote parts of the country. But the next words of the Chief set my mind at rest on that point.

“We want you to stay in New York and take up your life just where you left it off to-day. We want you to get back into Society and become a regular lounge lizard if necessary. And we want you to let the Department help you with hints when it can. But for the rest, you and Moore are to work together. It will be safer and better for both of you. Will you do it?”

“I’ll do it,” I told him.