He looked up, to stare curiously at his friend. "Have you been here
before, Nightspore?"

"I guessed Krag would leave a message."

"Well, I don't know--it may be a message, but it means nothing to
us, or at all events to me. What are 'back rays'?"

"Light that goes back to its source," muttered Nightspore.

"And what kind of light would that be?"

Nightspore seemed unwilling to answer, but, finding Maskull's eyes
still fixed on him, he brought out: "Unless light pulled, as well as
pushed, how would flowers contrive to twist their heads around after
the sun?"

"I don't know. But the point is, what are these bottles for?"

While he was still talking, with his hand on the smaller bottle, the
other, which was lying on its side, accidentally rolled over in such
a manner that the metal caught against the table. He made a movement
to stop it, his hand was actually descending, when--the bottle
suddenly disappeared before his eyes. It had not rolled off the
table, but had really vanished--it was nowhere at all.

Maskull stared at the table. After a minute he raised his brows, and
turned to Nightspore with a smile. "The message grows more
intricate."