“I pretended to Machin this morning that Sissie had told me that she was sleeping out, and that I had forgotten to tell Machin.  It’s a good thing we haven’t engaged lady’s maids yet.  I can trust Machin.  I know she didn’t believe me this morning, but I can trust her.  You see, after Sissie’s strange behaviour these last few days....  One doesn’t know what to think.  And there’s something else.  Every morning for the last three or four weeks Sissie’s gone out somewhere, for an hour or two, quite regularly.  And where she went I’ve never been able to find out.  Of course with a girl like her it doesn’t do to ask too direct questions....  Ah!  I should like to have seen my mother in my place.  I know what she’d have done!”

“What would your mother have done?  She always seemed to me to be a fairly harmless creature.”

“Yes, to you!...  Do you think we ought to inform the police!”

“No!”

“I’m so glad.  The necklace and Sissie coming on top of each other!  No, it would be too much!”

“It never rains but it pours, does it?” observed Mr. Prohack.

“But what are we to do?”

“Just what your mother would have done.  Your mother would have argued like this:  Either Sissie is staying away against her will or she is staying away of her own accord.  If the former, it means an accident, and we are bound to hear shortly from one of the hospitals.  If the latter, we can only sit tight.  Your mother had a vigorous mind and that is how she would have looked at things.”

“I never know how to take you, Arthur,” said Mrs. Prohack, and went on:  “And what makes it all the more incomprehensible IA that yesterday afternoon Sissie went with me to Jay’s to see about the wedding-dress.”

“But why should that make it all the more incomprehensible?”

“Don’t you think it does, somehow?  I do.”

“Did she giggle at Jay’s?”

“Oh, no!  Except once.  Yes, I think she giggled once.  That was when the fitter said she hoped we should give them plenty of time, because most customers rushed them so.  I remember thinking how queer it was that Sissie should laugh so much at a perfectly simple remark like that.  Oh!  Arthur!”

“Now, my child,” said Mr. Prohack firmly.  “Don’t get into your head that Sissie has gone off hers.  Yesterday you thought for quite half an hour that I was suffering from incipient lunacy.  Let that suffice you for the present.  Be philosophical.  The source of tranquillity is within.  Remember that, and remind me of it too, because I’m apt to forget it....  We can do nothing at the moment.  I will now get up, and I warn you that I shall want a large breakfast and you to pour out my coffee and read the interesting bits out of The Daily Picture to me.”