und which at that very moment came from the
blue wall beyond the bed!

How can we analyze our sense of hearing? Do you know the sound of your
wife's footsteps? When you were young, could you pick out the approach
of your father by the sound of his walk? Yes. But can you tell how? Are
you able to say what it is that distinguishes it from the sounds a
hundred other men would make going by your closed door? No. And neither
can I tell you why I recognized this sound.

All that I can say is this,--the wall was opaque, the sound so faint as
to be hardly heard, and yet I knew, as well as if the partition had been
of plate glass, that the impact was that of a human body!...

There was something in this sound on the wall which drew an involuntary
exclamation from me as the jar of forceps draws a tooth. And the sound
of my voice, sharp and explosive, woke the child.

She stared up at me with that strange look of infinity--I must so
describe it--infinity; then, as if she too had heard, she turned toward
the wall.

"What do you see?" I asked near her ear.

She gave me one of her tender smiles and made a little gesture as if to
say that she felt her inability to express something.

"It is there?" I asked, indicating the blank wall at last.

Her eyes sought that space of mysterious blue. Then she whispered,
"Yes."

I must say that, though I knew no more than I had at first, I derived
some satisfaction from the mere fact that for the second time Virginia
had confirmed the extraordinary belief or fancy which had possessed
prosaic MacMechem, the unimaginative Miss Peters, and, finally, myself.
It seemed to justify positive steps in an investigation; after a further
examination of the little body on the bed which offered still better
evidence of an improvement in the course of the malady, I left the
Marburys' door, determined to settle the question once and for all.

CHAPTER II

A MOVING FIGURE

It may strike you as absurd that I did not accept the possibility that
Virginia was suffering from delirium. I confess that, after I had closed
the house door behind me, I was for the moment convinced of the
connection between congestion at the base of the brain and the abnormal
fancy of the child. I had come to the house on foot, no vehicle was
waiting for me, and I remember that when I started off I turned in the
direction leading away from the Estabrooks' door.