Dr. Hartmann--the detective saw that it was he,
with Mayer--had switched on the violet light, and he once more felt its
blinding radiance upon his face.

Hartmann opened the door. "I shall be back again in a few hours," he
said, as he left the room. "I hope that by that time you will have quite
recovered your senses."

The detective made no reply. He had definitely made up his mind upon one
point: he was not going to purchase his freedom at the expense of his
duty. The unfortunate situation in which he now found himself was, he
knew very well, entirely his own fault, and his desire to atone for his
momentary carelessness made him determined not to accede to Dr.
Hartmann's demands. He hoped that his friends outside--Lablanche,
Dufrenne, even Grace--might be able to come to his assistance. If he
could only know that the snuff box was safe in Monsieur Lefevre's hands,
the rest did not matter much.

These thoughts passed through his mind as he lay with closed eyes, his
face quivering under the dazzling light which fell upon it. Its
intensity was, he thought, greater, if anything, than it had been
before, and the irritating effect upon his eyes more pronounced. He did
not open his eyes at all, on this occasion, for fear even a momentary
exposure would increase their sensitiveness.

Slowly the day passed. He concluded that it was afternoon, when he heard
far off a bell striking the hour of two, although it might equally well
have been two o'clock in the morning, for all he could tell. There was a
faint hum of conversation in the laboratory above him, which convinced
him that it was still day.

Presently his ear, acutely sensitive to the slightest noise which might
disturb the stillness about him, became aware of a faint sound of music,
which seemed to come to him from a long distance off. It was a popular
French march, and from a certain quality of the notes he concluded that
it was being played upon a phonograph. The strains of the music
distracted him, took his mind from the things about him, and as he
listened to it, it seemed that the effort of keeping his eyes tightly
closed grew sensibly less, the blinding pressure of the unwavering light
cone upon his face appreciably easier to bear. He knew that this was but
a momentary relief, but he welcomed it eagerly. Lying in this terrifying
silence, under the cruel glare of light, had become frightful--he
wondered if, after all, his nerves, his mind, could long stand the