“You’ll know in ten minutes,” she said.  “Now don’t bother me with any questions.  I’ve got directions for you.  You’re coming with me to the floor below.  I’ll let you into a hall closet.  It was built into a—­into a room, and the back of it is only wood.  There’s an old gas connection, which they papered over, through that wood.  Yesterday I punched through the paper and hung a picture over the hole.  This afternoon, I took that picture down.  To-morrow morning, the picture goes back.  But now, there’s a peephole into the room.”

Dr. Blake bristled.

“Peep through a hole!” he said.

“Now ain’t that just like a fashionable bringin-up,” said Rosalie, almost raising her voice.  “Things a gentleman can do an’ things he can’t do!  You’re tryin’ to bust a crook, an’ you remember what your French nurse told you about the etiquette of keyholes!”

“You’re my master at argument, Mme. Le Grange,” responded Blake.  “Go ahead.”

“And you promise to leave quiet?”

“I promise.”

“There’s one place I can trust your bringin’-up, I guess.  When you’re inside, feel about till you find a hassock.  Stand on it; ’t will bring your eyes up to the hole.  Stay there until I knock for you to come out—­let’s be goin’.”

“But what am I to do—­why am I here if I am to do nothing?”

“You’re to look an’ see an’ remember what you see—­that’s all for to-night.”

At the door, she looked him full in the eyes again: 

“Remember, you’ve promised.”

“I remember.”

The dim light of a low gas jet illuminated the upper hall.  From below came the faintest murmur of voices.  Rosalie led to the hall of the second floor, turned toward the back of the house, opened a door and motioned.  He stepped inside; the door closed without noise.  He was in black darkness.

His foot found the hassock; he mounted it and adjusted his eye.  He was looking into some kind of a living-room or boudoir.  On the extreme left of his range of vision he could see a set of dark portieres; directly before him was a foolish little white desk, over which burned a gas jet, turned low.  That, apparently, was the only illumination in the room.  For the rest, he could only see a wall decorated with the tiny frivolities of a boudoir, two chairs, a sewing table.  He watched until—­his eyes, grown accustomed to the dim light—­he discerned every detail.  From far below, he heard the subdued hum of a conversation, and made out at length, in the rise and fall of voices, that a man and a woman were speaking.  Then even that sound ceased; over the house lay a stillness so heavy that he feared his own breathing.

Gradually, he was aware that someone was playing a piano.  It began so gently that he doubted, at first, whether it was not a far echo from one of the houses to right or left.  But it increased in volume until he located it definitely in the rooms below.  The air, unrecognized at first, called up a memory of old-fashioned parlors and of his grandmother.  He found himself struggling for words to fit the tune; and suddenly they sprang into his mind—­“Wild roamed an Indian maid, bright Alfaretta.”  Thrice over the unseen musician played the air, and let it die with a last, lingering chord.