tness had
left it.

As Jim watched, inquiringly, Clee moved his right hand a little, and
once more the dial leaped out through the dimness with unnatural
brilliance. Jim saw that his friend was holding in this hand the
package of tobacco. Clee repeated the demonstration.

"The dial glows with unusual brightness always--except when I hold the
package of tobacco in front of it at this spot," he said wonderingly,
half to himself. "If I remember my science right, ultra-violet light
would make the radium on the dial glow; and the lead in the tin-foil
of the tobacco wrapping would screen it off. Let's see--"

He crossed to the other side of the room and held his watch and the
package of tobacco in various positions until he again found one line
along which the watch-dial gave off only its customary light.

"Yes," he said, "--exactly in the extended line made by my watch and
this package of tobacco is the source of the ray which makes the
watch-dial glow. It's probably the control room of this ship."

"An extraordinary deduction, my dear Sherlock," commented Wilson
drily; "and valuable. I wish you'd now take a moment and deduce the
reason for the mysterious appearance of the lumps on the back of our
necks. I know I didn't have mine before I was taken for this
sky-ride."

* * * * *

As he spoke, his hand sought the back of his neck where there was a
fat lump about the size of a quarter--a lump not painful, for all its
newness and size. Hard pushing with probing fingers had revealed
something that seemed to be hard and flat, buried within; but close
examinations failed to show any wound or scar, and the men had no
notion what the lumps might be. Clee's was just like Jim's.

But Clee did not respond to his friend's invitation. A heavy mood had
come over him; he was standing by the outer wall, looking out. Jim
went and stood beside him, his hand on his shoulder, and together they
gazed through the cherry-crystal wall of their prison ship out on the
loneliness of the immeasurable miles outside. For them, space was red,
instead of the deep black they knew they would see through colorless
glass. Brilliant pinpoints of light, millions of them, in all sizes,
made up the infinite space that was the background of their adventure.

To which one--near which one were they going? Would they ever return
to their Earth again? Would their friends ever know of the incredible
adventure that had overtaken