to them
strengthened his resolve. One more chance--and this time he would not
fail or waver.

"Brad--look!"

Vibrant with surprise and urgency, the words ripped aside the veil of
Nellon's thoughts. His head jerked up.

Big Tim was on his feet. He was pointing up at the steep bank of the
gorge down which they had tumbled.

Most of the disturbed snow had settled and the wind had carried away the
rest. Nellon could see quite clearly.

There up on the bank, a small snow slide had taken place. And now,
against the unbroken monotony of white, something gleamed in vivid
contrast.

Nellon squinted. Gradually he began to make out details. The strange
surface revealed by the slide seemed to have the mellow hue of bronze,
but Nellon could not be sure, since it was queerly dappled and flecked
with tones of gold and red. He thought it must be from the strain on his
eyes, and closed them momentarily. But when he looked again the colors
were as weird as he had last seen them. This time, however, he made out
a detail which he had missed previously. The surface seemed to be
crossed by a black line or stripe.

"Now what in the world can that be?" Tim Austin's voice was wondering,
vaguely troubled. "It's like no sample of rock or soil we've taken.
Metal--that's what it is!" he exclaimed of a sudden. "It's an exposed
vein of some metal. Come on, Brad, let's have a look at it."

Nellon got to his feet, his eyes fixed upon that uncanny patch of
something which stood out against the surrounding whiteness like a smear
of blood.

Big Tim was already started up the bank. Nellon sucked in a breath and
followed after him.

* * * * *

The climb was a hard and difficult one, and their recent physical
jarring caused by the fall made it all the harder. But curiosity pulled
them on like a vast magnet. In the exertion they forgot their aches and
bruises. Slipping and sliding, clutching for handholds, floundering in
loose drifts which filled pockets of hardened crust, they made their way
slowly but surely up the bank.

Finally they stood before that strangely mottled patch of red and brown
and gold. The mood of awed wonder which gripped them at once heightened
and deepened.

"It _is_ metal!" Tim Austin breathed. "But--but, Brad, it's not a vein.
It's--"

"It's a door!" Nellon finished hoarsely.

It was a door, a metal door in the snow covered bank of a falls that
had, in some long, long ago, solidified