“I see,” commented Kennedy.  “You know women of the type who frequent the Futurist and the Montmartre are always running to the hairdressing and manicure parlours.  They make themselves ‘beautiful’ under the expert care of the various specialists and beauty doctors.  Then, too, they keep in touch that way with what is going on in the demi-monde.  That is their club, so to speak.  It is part of the beauty shop’s trade to impart such information—­at least of a beauty shop in this neighbourhood.”

I regarded the place curiously.

“Come, Walter, don’t stare,” nudged Kennedy.  “Let’s take a turn down to the Prince Henry and wait.  We can get a bite to eat, too.”

I had hardly expected that the pickpocket would play fair, but evidently the lure of the remaining twenty dollars was too strong.  We had scarcely finished our dinner when he came in.

“Here it is,” he whispered.  “The house man here at the Prince Henry knows me.  Slip me the twenty.”

Kennedy leisurely tore the wrappings from the packet.

“I suppose you have already looked at this first and found that it isn’t worth anything to you compared to twenty dollars.  Anyhow, you kept your word.  Hello—­what is it?”

He had disclosed several small packets.  Inside each, sealed, was a peculiar glistening whitish powder.

“H’m,” mused Kennedy, “another job for the chemist.  Here’s the bankroll.”

“Thanks,” grinned the dip as he disappeared through the revolving door.

We had returned to the laboratory that night where Kennedy was preparing to experiment on the white powder which he had secured in the packet that came from Dr. Harris.  The door opened and Clare Kendall entered.

“I’ve been calling you up all over town,” she said, “and couldn’t find you.  I have something that will interest you, I think.  You said you wanted something written by Dr. Harris.  Well, there it is.”

She laid a sheet of typewriting on the laboratory table.

“How did you get it?” asked Kennedy in eager approbation.

“When I left you at the Futurist Tea Room to follow that woman Marie in the cab, I had a good deal of trouble.  I guess people thought I was crazy, the way I was ordering that driver about, but he was so stupid and he would get tangled up in the traffic on Fifth Avenue.  Still, I managed to hang on, principally because I had a notion already that she was going to the Montmartre.  Sure enough, she turned down that block, but she didn’t go into the hotel after all.  She stopped and went into a place two doors down--Mme. Margot’s Beauty Parlour.”

“Just where we finally saw Harris go,” exclaimed Kennedy.  “I beg your pardon for interrupting.”