She was looking down the corridor toward the desk when she saw something that caused her to change her mind.  There was the young lady who had been talking so flippantly to the woman with a grievance, and she was now talking, of all people, to Drummond!

Constance shrank back into her wicker chair in the protecting angle.  What did it mean?  If Drummond had anything to do with it, even remotely, it boded no good, at least.

Suddenly a possible explanation crossed her mind.  Was it a side-light upon that peculiar industry of divorce as practiced in no place except New York?

It was not only that Constance longed for, lived by excitement.  She felt a sense of curiosity as to what the detective was up to now.  And, somehow, she felt a duty in the case.  She determined to return the envelope and card, and meet the woman.  And the more she thought of it the more imperative became the idea.

So it came about that the following forenoon Constance sought out the Melcombe Apartments, a huge stone and brick affair on a street which the uptown trend of population was transforming.

Anita Douglas, she had already found out by an inquiry or two, was the wife of a well-known business man.  Yet, as she entered the little apartment, she noticed that there was no evidence about it of a man’s presence.

Mrs. Douglas greeted her unexpected visitor with an inquiring look.

“I was passing through the corridor of the Vanderveer yesterday afternoon,” began Constance, leaping into the middle of her errand, “and I happened to see this envelope lying on the carpet.  I thought first of destroying it; then that perhaps you would rather destroy it yourself.”

Mrs. Douglas almost pounced on the letter as Constance handed it to her.  “Thank you,” she exclaimed.  “It was very thoughtful of you.”

For a moment or two they chatted of inconsequential things.

“Who was your friend?” asked Constance at length.

The woman caught her breath and flushed a bit, evidently wondering just how much Constance really knew.

“The young lady,” added Constance, who had put the question in this form purposely.

“Why do you ask?” Mrs. Douglas inquired in a tone that betrayed considerable relief.

“Because I can tell you something of her, I think.”

“A friend of mine—­a Mrs. Murray.  Why?”

“Aren’t you just a little bit afraid of—­er—­friends that you may chance to make in the city?” queried Constance.

“Afraid?” repeated the other.

“Yes,” said Constance, coming gradually to the point.  “You know there are so many detectives about.”

Mrs. Douglas laughed half nervously.  “Oh, I’ve been shadowed,” she replied confidently.  “I know how to shake them off.  If you can’t do anything else, you can always take a taxi.  Besides, I think I can uncover almost any shadow.  All you have to do, if you think you’re being shadowed, is to turn a corner and stop.  That uncovers the shadow as soon as he comes up to the corner, and after that he is useless.  You know him.”