he had been immediately aware of the physical benefit of the exercise.  The household was supposed to know naught of the affair, but the kitchen knew a good deal about it somehow; the kitchen was pleasantly and rather condescendingly excited, and a little censorious, for the reason that nobody in the kitchen had ever before lived in a house the master of which being a parent of adult children took surreptitious lessons in dancing; the thing was unprecedented, and therefore of course intrinsically reprehensible.  Mr. Prohack guessed the attitude of the kitchen, and had met Machin’s respectful glance with a self-conscious eye.

He now bolted the front-door and went upstairs extinguishing the lights after him.  Eve had told her husband and child that she should go to bed early.  He meant to have a frolicsome, teasing chat with her, for the doctor had laid it down that light conversation would assist the cure of traumatic neurasthenia.  She would not be asleep, and even if she were asleep she would be glad to awaken, because she admired his style of gossip when both of them were in the vein for it.  He would describe for her the evening at the studio humorously, in such a fashion as to confirm her in her righteous belief that the misguided Sissie had seen the maternal wisdom and quitted dance-studios for ever.

The lamps were out in the bedroom.  She slept.  He switched on a light, but her bed was empty; it had not been occupied!

“Marian!” he called in a low voice, thinking that she might be in the boudoir.

And if she was in the boudoir she must be reclining in the dark there.  He ascertained that she was not in the boudoir.  Then he visited both the drawing-room and the dining-room.  No Marian anywhere!  He stood a moment in the hall and was in a mind to ring for Machin—­he could see from a vague illumination at the entrance to the basement steps that the kitchen was still inhabited—­but just then all the servants came upwards on the way to the attics, and at the strange spectacle of their dancing master in the hall they all grew constrained and either coughed or hurried as though they ought not to be caught in the act of retiring to bed.

Mr. Prohack, as it were, threw a lasso over Machin, who was the last of the procession.

“Where is your mistress, Machin?” He tried to be matter-of-fact, but something unusual in his tone apparently started her.

“She’s gone to bed, sir.  She told me to put her hot-water bag in the bed early.”

“Oh!  Thanks!  Good-night.”

“Good-night, sir.”

He could not persuade himself to call an alarm.  He could not even inform Machin that she was mistaken, for to do so would have been equivalent to calling an alarm.  Hesitating and inactive he allowed the black-and-white damsels and the blue cook to disappear.  Nor would he disturb Sissie—­yet.  He had first to get used to the singular idea that his wife had vanished from home.  Could this vanishing be one of the effects of traumatic neurasthenia?  He hurried about and searched all the rooms again, looking with absurd carefulness, as if his wife were an insignificant object that might have dropped unperceived under a chair or behind a couch.