“It was lying there and I picked it up.  I don’t see any harm in that.”

“You probably meant none.  You couldn’t have known the part it had just played in this tragic drama,” said the old detective looking carefully at the cutter which he had taken in his hand, but not so carefully that he failed to note that the look of distress was not lifted from the mother’s face either by her daughter’s words or manner.

“You have washed this?” he asked.

“No.  Why should I wash it?  It was clean enough.  I was just going down to give it in at the desk.  I wasn’t going to carry it away.”  And she turned aside to the window and began to hum, as though done with the whole matter.

The old detective rubbed his chin, glanced again at the paper-cutter, then at the girl in the window, and lastly at the mother, who had lifted her head again and was facing him bravely.

“It is very important,” he observed to the latter, “that your daughter should be correct in her statement as to the condition of this article when she picked it up.  Are you sure she did not wash it?”

“I don’t think she did.  But I’m sure she will tell you the truth about that.  Caroline, this is a police matter.  Any mistake about it may involve us in a world of trouble and keep you from getting back home in time for your coming-out party.  Did you—­did you wash this cutter when you got upstairs, or—­or—­” she added, with a propitiatory glance at Mr. Gryce—­“wipe it off at any time between then and now?  Don’t answer hastily.  Be sure.  No one can blame you for that act.  Any girl, as thoughtless as you, might do that.”

“Mother, how can I tell what I did?” flashed out the girl, wheeling round on her heel till she faced them both.  “I don’t remember doing a thing to it.  I just brought it up.  A thing found like that belongs to the finder.  You needn’t hold it out towards me like that.  I don’t want it now; I’m sick of it.  Such a lot of talk about a paltry thing which couldn’t have cost ten dollars.”  And she wheeled back.

“It isn’t the value.”  Mr. Gryce could be very patient.  “It’s the fact that we believe it to have been answerable for Miss Challoner’s death—­that is, if there was any blood on it when you picked it up.”

“Blood!” The girl was facing them again, astonishment struggling with disgust on her plain but mobile features.  “Blood! is that what you mean.  No wonder I hate it.  Take it away,” she cried.

“Oh, mother, I’ll never pick up anything again which doesn’t belong to me!  Blood!” she repeated in horror, flinging herself into her mother’s arms.

Mr. Gryce thought he understood the situation.  Here was a little kleptomaniac whose weakness the mother was struggling to hide.  Light was pouring in.  He felt his body’s weight less on that miserable foot of his.

“Does that frighten you?  Are you so affected by the thought of blood?”