“Here is a clothing store,” she said. “Go in and buy what you need. You must not go back to the rooms now. The hotel is probably watched. It’s a wonder we all got away from there as we did after the meeting. You buy what you need here, and I’ll wait in front of the store. Change your appearance as much as possible.”

Nick was sorely puzzled. Why should the woman want him to change his clothes? She understood that the officers knew Mantelle, and that they would find him if they wanted to do so in whatever suit he might put on. Was it her purpose to escape when he went into the store to change his clothes? That was a risk he could not run, and he hesitated at the store door. Then a messenger in uniform paused at the door, looked at the number, and passed on.

“That’s Patsy, all right,” thought Nick; “here’s for the new clothes. She can’t get away so long as he is here. This is a mystery, but I’ll solve it!”

Nick selected a large, light-colored suit, and put it on over the Mantelle disguise. The hat he retained, for he could not very well conceal the derby he had worn. When he left the dressing room he seemed like another person. The woman looked pleased, and asked where the other clothes were.

“I have them where I can get them again,” was the reply.

Once more in the street, the woman turned at the corner of Houston and walked in the direction of the East River. She seemed strangely agitated over something, and more than once Nick thought she was laughing immoderately.

The detective began to think he had caught a Tartar. At least, he could not make up his mind as to what was coming off next.

The house she presently entered was in the same block with the ruins of the burned headquarters of the Great Diamond Syndicate.

She led the way up a staircase, and entered a suite of rooms which faced the street. Closing the door, she laid aside her hat and coat and faced the detective with a smile.

She was a handsome woman, tall, slender, and fair of face, but certainly not the one Nick had seen at the café with Mantelle. She said: