There was something in this.  Elsa, I knew, was jealous, and her pride had been hurt because Louis had taken the rose she gave him, and then had gone to call on another girl.  But I had no reason to doubt Elsa’s statement, and I had every reason to doubt Louis’s.  I tried to imagine what Louis’s experience had really been, and it suddenly occurred to me, that though innocent himself of real wrong, he had seen something in the office, or through the office windows that he wished to keep secret.  I did not for a moment believe that the man had killed his master, so I concluded he was endeavoring to shield someone else.

“Louis,” I said, suddenly, “I’ll tell you what you did.  You went around by the office, you saw a light there late at night, and you naturally looked in.  You saw Mr. Crawford there, and he was perhaps already killed.  You stepped inside and discovered this, and then you came away, and said nothing about it, lest you yourself be suspected of the crime.  Incidentally you dropped two petals from the rose Elsa had given you.”

Louis’s answer to this accusation was a perfect storm of denials, expressed in voluble French and broken English, but all to the effect that it was not true, and that if he had seen his master dead, he would have raised an alarm.

I saw that I had not yet struck the right idea, so I tried again.  “Then, Louis, you must have passed the office before Mr. Crawford was killed, which is really more probable.  Then as you passed the window, you saw something or someone in the office, and you’re not willing to tell about it.  Is this it?”

This again brought forth only incoherent denial, and I could see that the man was becoming so rattled, it was difficult for him to speak clearly, had he desired to do so.

“Elsa,” I said, suddenly, “you took that rose from Louis’s room.  What did you do with it?”

“I kept,—­I mean, I don’t know what I did with it,” stammered the girl, blushing rosy red, and looking shyly at Louis.

I felt sorry to disclose the poor girl’s little romance, for it was easy enough to see that she was in love with the fickle Frenchman, who evidently did not reciprocate her interest.  He looked at her disdainfully, and she presented a pathetic picture of embarrassment.

But the situation was too serious for me to consider Elsa’s sentiments, and I said, rather sternly:  “You do know where it is.  You preserved that rose as a souvenir.  Go at once and fetch it.”

It was a chance shot, for I was not at all certain that she had kept the withered flower, but dominated by my superior will she went away at once.  She returned in a moment with the flower.

Although withered, it was still in fairly good condition; quite enough so for me to see at a glance that no petals had been detached from it.  The green calyx leaves clung around the bud in such a manner as to prove positively that the unfolding flower had lost no petal.  This settled the twelfth rose.  Wherever those tell-tale petals had come from, they were not from Louis’s rose.  I gave the flower back to Elsa, and I said, “take your flower, my girl, and go away now.  I don’t want to question you any more for the present.”