attracted his attention, the girl extended a white-gloved hand from
the window and dropped a note upon the edge of the pavement.
Immediately she withdrew into the vehicle--which moved away at
accelerated speed, swung around the next corner and was gone.

Stuart ran forward and picked up the note. Without pausing to read it,
he pressed on to the corner. The cab was already two hundred yards
away, and he recognized pursuit to be out of the question. The streets
were almost deserted at the moment, and no one apparently had
witnessed the episode. He unfolded the sheet of plain note-paper,
faintly perfumed with jasmine, and read the following, written in an
uneven feminine hand:

"Close your shutters at night. Do not think too bad of me."




CHAPTER XI

THE BLUE RAY


Dusk found Stuart in a singular frame of mind. He was torn between
duty--or what he conceived to be his duty--to the community, and ...
something else. A messenger from New Scotland Yard had brought him a
bundle of documents relating to the case of Sir Frank Narcombe, and
a smaller packet touching upon the sudden end of Henrik Ericksen, the
Norwegian electrician, and the equally unexpected death of the Grand
Duke Ivan. There were medical certificates, proceedings of coroners,