“And then?”

Oh, then she was so frightened and so shocked that everything swam before her eyes and she nearly fell!  Her heart was not a strong one and sometimes missed a beat or two, and she thought it must have done so then, for when her head steadied again, she found herself clinging to the balustrade of the great staircase.

“Then you have nothing whatever to add to what the others have told?”

Her “no,” if a shaky one, was decisive, and seeing no reason for detaining her further, he gave her permission to depart.

Disturbed in his calculations, but not disheartened, Mr. Gryce next proceeded to interrogate the door-man at this end of the building.  From his position, facing as he did the approach from the small staircase, he should be able to say, if the old lady could not, whether anyone had crossed the open strip of court toward which she had been advancing.  But Mr. Gryce found him no more clear-headed on this point than she.  He was the oldest man connected with the museum, and had been very much shaken up by what had occurred.  Really, he could not say whether anyone had passed across his line of vision at that time or not.  All he could be sure of was that no attempt had been made by anyone to reach the door after he had been bidden to close it.

So this clue ended like the rest in no thoroughfare.  Would he have any better luck with the subject of his next inquiry?  The young lady tabulated as No. 13 was where she could have seen the upper edge of the tapestry shake if she had been looking that way; but she was not.  She also was going from instead of toward the point of interest—­in other words, entering and not leaving the room on whose threshold she stood.

Only two men were left from whom he could hope to obtain the important testimony he was so anxiously seeking:  Nos. 10 and 11.  He had turned back toward the bench where they should be awaiting his attention and was debating whether he would gain more by attacking them singly or together, when he suddenly became aware of a fact which drove all these small considerations out of his mind.

According to every calculation and according to the chart, there should be only these two men on that bench.  But he saw three.  Who was this third man, and where had he come from?

VI

THE MAN IN THE GALLERY

Beckoning to Sweetwater, Mr. Gryce pointed out this extra man and asked him if he recognized him as one of the twenty-two he had tabulated.

The answer was a vigorous no.  “It’s a new face to me.  He must have dropped from the roof or come up through the flooring.  He certainly wasn’t anywhere about when I made out my list.  He looks a trifle hipped, eh?”

“Troubled—­decidedly troubled.”

“You might go a little further and say done up.”

“Good-looking, though.  Appears to be of foreign birth.”