uch of fading sunlight upon the Apennines. Up near the South Pole,
Tycho with its radiating open rills stood like a grim dark maw.

Miko bent over a plate. "Something here? Is there?"

An abnormality upon the frowning ragged cliffs of Tycho? We thought
so. But then it seemed not.

Another hour. No signal came from Earth. If Snap's calls were getting
through we had no evidence of it. Abruptly Miko strode at me from
across the room. I went cold and tense; Moa shifted, alert to my every
movement. But Miko was not interested in me. A sweep of his clenched
fist knocked the ultra-violet sender and its coils and mirrors in a
tinkling crash to the grid at my feet.

"We don't need that, whatever it is!" He rubbed his knuckles where the
violet waves had tinged them, and turned grimly back to Snap.

"Where are your ray mirrors? If the treasure lies exposed--"

This Martian's knowledge was far greater than we believed. He grinned
sardonically at Anita. "If our treasure is here on this hemisphere,
Prince, we should pick up its rays. Don't you think so? Or is
Grantline too cautious to leave it exposed?"

Anita spoke in a careful, throaty drawl. "The rays came through enough
when we passed here on the way out."

"You should know," grinned Miko. "An expert eavesdropper, Prince, I
will say that for you.... Come, Dean, try something else. By God, if
Grantline does not signal us, I will be likely to blame you--my
patience is shortening. Shall we go closer, Haljan?"

"I don't think it would help," I said.

He nodded. "Perhaps not. Are we checked?"

"Yes." We were poised very nearly motionless. "If you wish an advance,
I can ring it. But we need a surface destination now."

"True, Haljan." He stood thinking. "Would a zed-ray penetrate those
crater cliffs? Tycho, for instance, at this angle?"

"It might," Snap agreed. "You think he may be on the northern inner
Tycho?"

"He may be anywhere," said Miko shortly.

"If you think that," Snap persisted, "suppose we swing the _Planetara_
over the South Pole. Tycho, viewed from there--"

"And take another quarter day of time?" Miko sneered. "Flash on your
zed-ray; help him hook it up, Haljan."

I moved to the lens box of the spectroheliograph. It seemed that Snap
was very strangely reluctant. Was it because he knew that the
Grantline camp lay concealed on the north inner wall of Tycho's giant
ring? I thought so. But Snap flashed a queer look at Anita. She did
not see it, but I di