Professor Seigfried sat there looking at her with dropped jaw, but he made no reply.

“If you will excuse my saying so,” the girl went on, “you are acting very childishly. It is evident to me that you are no criminal, yet if the Director of Police had been in my place he would have arrested you long ago, and that merely because of your own foolish actions.”

“The map proved nothing,” he said at last, haltingly, “and besides, both you and the Director will now have some difficulty in finding it.”

“That is further proof of your folly. The Director doesn’t need to find it. I am here to testify that I saw the map, saw the curved line passing through the Treasury, and saw you destroy what you thought was an incriminating piece of evidence. It would be much better if you would deal as frankly with me as I have done with you. Then I shall give you the best advice I can—if my advice will be of any assistance to you.”

“Yes, and publish it to all the world.”

“It will have to be published to all the world in any case, for, if I leave here without full knowledge, I will simply go to the police office and there tell what I have learned in this room.”

“And if I do speak, you will still go to the Director of the Police and tell him what you have discovered.”

“No, I give you my word that I will not.”

“What guarantee have I of that?” asked the old man suspiciously.

“No guarantee at all except my word!”