And Jolly Roger, in response to that signal-tapping, heard nothing from within, except a monotone of voice that came from the outer room.

For half an hour he waited, repeating the signals at intervals.

At last a door opened, and Nada stood silhouetted against the light of the room beyond.
McKay tapped again, very lightly, and the door closed quickly behind the girl.

In a moment she was at the window, which was raised a little from the bottom.
"Mister--Roger--" she whispered.

"Is it--YOU ?" "Yes," he said, finding a little hand in the darkness.