The duke and I were both listening attentively.

“I was frightened, and lay still a little; but then I got up—­for the sounds went on—­and put on some clothes, and came down—­”

“Why didn’t you rouse the men?  It must be thieves.”

“I did go to the men’s room; but their door was locked, and I could not make them hear.  I did not dare to knock loud; but I saw a light in the room, under the door; and if they’d been awake they would have heard.”

“Perhaps they weren’t there,” I suggested.

Suzanne turned a sudden look on me.  Then she said: 

“The safe holding the jewels is fixed in the wall of the duchess’ dressing room.  And—­and Lafleur knows it.”

The duke had heard the story with a frowning face; but now a smile appeared on his lips, and he said: 

“Ah, yes!  The jewels are there!”

“The—­the Cardinal’s Necklace,” whispered Suzanne.

“True,” said the duke; and his eyes met mine, and we both smiled.  A few minutes ago it had not seemed likely that I should share a joke—­even a rather grim joke—­with him.

“Mr. Aycon,” said he, “are you inclined to help me to look into this matter?  It may be only the girl’s fancy—­”

“No, no; I heard plainly,” Suzanne protested eagerly.

“But one can never trust these rascally men-servants.”

“I am quite ready,” said I.

“Our business,” said he, “will wait.”

“It will be the better for waiting.”

He hesitated a moment; then he assented gravely: 

“You’re right—­much better.”

He took a pistol out of the drawer, and shut and locked the drawer.  Then he turned to Suzanne and said: 

“You had better go back to bed.”

“I daren’t, I daren’t!”

“Then stay here and keep quiet.  Mind, not a sound!”

“Give me a pistol.”

He unlocked the drawer again, and gave her what she asked.  Then signing to me to follow him, he opened the door, and we stepped together into the dark hall, the duke laying his hand on my arm and whispering: 

“They’re after the necklace.”

We groped slowly, with careful noiselessness, across the hall to the foot of the great staircase.  There we paused and listened.  There was nothing to be heard.  We climbed the first flight of stairs, and the duke turned sharp to the right.  We were now in a short corridor which ran north and south; three yards ahead of us was another turn, leading to the west wing of the house.  There was a window by us; the duke gently opened it; and over against us, across the base of the triangle formed by the building, was another window, four or five yards away.  The window was heavily curtained; no light could be seen through it.  But as we stood listening, the sounds began—­first the gentle muffled hammering, then the sound of the file.  The duke still held my arm, and we stood motionless.  The sounds went on for a while.  Then they ceased.  There was a pause of complete stillness.  Then a sharp, though not loud, click!  And, upon this, the duke whispered to me: