He got no further in his soliloquy, for Mrs. Octagon swept into the room in her most impressive manner.  She was calm and cool, and her face wore a smile as she advanced to the detective.  “My dear Mr. Jennings,” she said, shaking him warmly by the hand, “I am so glad to see you, though I really ought to be angry, seeing you came to my house so often and never told me what you did.”

“You mightn’t have welcomed me had you known,” said he dryly.

“I am above such vulgar prejudices,” said Mrs. Octagon, waving her hand airily, “and I am sure your profession is an arduous one.  When Juliet told me that you were looking into this tragic death of my poor sister I was delighted.  So consoling to have to do with a gentleman in an unpleasant matter like this.  Why have you come?”

This last question was put sharply, and Mrs. Octagon fastened her big black eyes on the calm face of the detective.  “Just to have a look at the house,” he said readily, for he was certain Juliet would not report their conversation to her mother.

Mrs. Octagon shrugged her shoulders.  “A very nice little house, though rather commonplace in its decoration; but my poor sister never did have much taste.  Have you discovered anything likely to lead to the discovery of her assassin?”

“I am ashamed to say I am quite in the dark,” replied Jennings.  “I don’t suppose the truth will ever be discovered.”

The woman appeared relieved, but tried to assume a sad expression.  “Oh, how very dreadful,” she said, “she will lie in her untimely grave, unavenged.  Alas!  Alas!”

But Jennings was not mystified by her tragic airs.

He was certain she knew something and feared lest it should come to his knowledge.  Therefore he resolved to startle her by a blunt question.  “I never knew you were acquainted with Maraquito!”

Mrs. Octagon was not at all taken aback.  “I don’t know such creatures as a rule,” she said calmly.  “What makes you think I do?”

“I saw you enter her house one night.”

“Last night,” said Mrs. Octagon coolly.  “Yes.  Maraquito, or Senora Gredos, or whatever she calls herself, told me you had just gone.  I saw her in a little room off the salon where the play went on.”

The detective was surprised by this ready admission, and at once became suspicious.  It would seem that Mrs. Octagon, expecting such a question, was uncommonly ready to answer it.  “May I ask why you went to see this woman?” he demanded.

An innocent woman would have resented this question, but Mrs. Octagon ostentatiously seized the opportunity to clear herself, and thereby increased Jennings’ suspicions.  “Certainly,” she said in an open manner and with a rather theatrical air, “I went to beg my son’s life from this fair siren.”

“What on earth do you mean?”

“Basil,” said Mrs. Octagon, in her deep, rich voice, “is too fond of this fair stranger—­Spanish, is she not?”