den explosion. This time the earth tremors not only hurled
them from their feet, but seemed to run along the walls and across the
ceiling. Ross, burying his face in the crook of his arm, could not rid
himself of the fear that the building was being slowly twisted into
scrap. When the shock was over he raised his head.

"What's going on?" He heard McNeil ask.

"Attack." That was Ashe. "But why, and by whom--don't ask me! You are a
prisoner, I suppose, Murdock?"

"Yes, sir." Ross was glad that his voice sounded normal enough.

He heard someone sigh and guessed it was McNeil. "Another digging
party." There was tired disgust in that.

"I don't understand," Ross appealed to that section of the dark where
Ashe had been. "Have you been here all the time? Are you trying to dig
your way out? I don't see how you can cut out of this glacier that we're
parked under----"

"Glacier!" Ashe's exclamation was as explosive as the tremors. "So we're
inside a glacier! That explains it. Yes, we've been here--"

"On ice!" McNeil commented and then laughed. "Glacier--ice--that's
right, isn't it?"

"We're collaborating," Ashe continued. "Supplying our dear friends with
a lot of information they already have and some flights of fancy they
never dreamed about. However, they didn't know we had a few surprise
packets of our own strewn about. It's amazing what the boys back at the
project can pack away in a belt, or between layers of hide in a boot. So
we've been engaged in some research of our own----"

"But I didn't have any escape gadgets." Ross was struck by the
unfairness of that.

"No," Ashe agreed, his voice even and cold, "they are not entrusted to
first-run men. You might slip up and use them at the wrong moment.
However, you appear to have done fairly well...."

The heat of Ross's rising anger was chilled by the noise which cracked
over their heads, ground to them through the walls, flattened and
threatened them. He had thought those first shocks the end of this ice
burrow and the world; he knew that this one was.

And the silence that followed was as threatening in its way as the
clamor had been. Then there was a shout, a shriek. The space of light
near the cell door was widening as that barrier, broken from its lock,
swung open slowly. The fear of being trapped sent the men in that
direction.

"Out!"

Ross was ready enough to respond to that order, but they were stopped by
a crackle of sound that could be only one thin