to explain my presence here? I am not the guardian of Rosa, and she may resent being tracked across Paris by a young man with no claim to watch her actions.”

Nevertheless, in an expedition of this nature one must accept risks, and therefore I knocked gently. There was no reply to the summons, and I was cogitating upon my next move when, happening to press against the door with my hand, I discovered that it was not latched. Without weighing consequences, I quietly opened it, and with infinite caution stepped into the hall, and pushed the door to. I did not latch it, lest I might need to make a sudden exit — unfamiliar knobs and springs are apt to be troublesome when one is in a hurry.

I was now fairly in the house, but the darkness was blacker than the pit, and I did not care