Margaret was studying her closely, and now for the first time she detected sincere emotion in Mollie’s voice—­and unforced tears in her eyes.  Hope was reborn.

“Perhaps you can,” she continued, speaking gently.  “You knew all Rita’s friends and all Sir Lucien’s.  You must have met the woman called Mrs. Sin?”

“Mrs. Sin,” whispered Mollie, staring in a frightened way so that the pupils of her eyes slowly enlarged.  “What about Mrs. Sin?”

“Well, you see, they seem to think that through Mrs. Sin they will be able to trace Kazmah; and wherever Kazmah is one would expect to find poor Rita.”

Mollie lowered her head for a moment, then glanced quickly at the speaker, and quickly away again.

“Please let me explain just what I mean,” continued Margaret.  “It seems to be impossible to find anybody in London who will admit having known Mrs. Sin or Kazmah.  They are all afraid of being involved in the case, of course.  Now, if you can help, don’t hesitate for that reason.  A special commission has been appointed by Lord Wrexborough to deal with the case, and their agent is working quite independently of the police.  Anything which you care to tell him will be treated as strictly confidential; but think what it may mean to Rita.”

Mollie clasped her hands about her right knee and rocked to and fro in her chair.

“No one knows who Kazmah is,” she said.

“But a number of people seem to know Mrs. Sin.  I am sure you must have met her?”

“If I say that I know her, shall I be called as a witness?”

“Certainly not.  I can assure you of that.”

Mollie continued to rock to and fro.

“But if I were to tell the police I should have to go to court, I suppose?”

“I suppose so,” replied Margaret.  “I am afraid I am dreadfully ignorant of such matters.  It might depend upon whether you spoke to a high official or to a subordinate one; an ordinary policeman for instance.  But the Home office agent has nothing whatever to do with Scotland Yard.”

Mollie stood up in order to reach an ash-tray, and: 

“I really don’t think I have anything to say, Miss Halley,” she declared.  “I have certainly met Mrs. Sin, but I know nothing whatever about her, except that I believe she is a Jewess.”

Margaret sighed, looking up wistfully into Mollie’s face.  “Are you quite sure?” she pleaded.  “Oh, Miss Gretna, if you know anything—­ anything—­don’t hide it now.  It may mean so much.”

“Oh, I quite understand that,” cried Mollie.  “My heart simply aches and aches when I think of poor, sweet little Rita.  But—­really I don’t think I can be of the least tiny bit of use.”

Their glances met, and Margaret read hostility in the shallow eyes.  Mollie, who had been wavering, now for some reason had become confirmed in her original determination to remain silent.  Margaret stood up.

“It is no good, then,” she said.  “We must hope that Rita will be traced by the police.  Good-bye, Miss Gretna.  I am so sorry you cannot help.”