st way we can get there?"

Ulv frowned in thought. "If you can drive one of the cars the
offworlders use, I know where there are some locked in buildings
in this city. None of my people know how they are made to move."

"I can work them--let's go."

Chance was with them this time. The first sand car they found still
had the keys in the lock. It was battery-powered, but contained
a full charge. Much quieter than the heavy atomic cars, it sped
smoothly out of the city and across the sand. Ahead of them the sun
sank in a red wave of color. It was six o'clock. By the time they
reached the tower it was seven, and Brion's nerves felt as if they
were writhing under his skin.

Even though it looked like suicide, attacking the tower brought
blessed relief. It was movement and action, and for moments at
a time he forgot the bombs hanging over his head.

The attack was nerve-rackingly anticlimactic. They used the main
entrance, Ulv ranging soundlessly ahead. There was no one in sight.
Once inside, they crept down towards the lower rooms where the
radiation had been detected. Only gradually did they realize that
the magter tower was completely empty.

"Everyone gone," Ulv grunted, sniffing the air in every room that
they passed. "Many magter were here earlier, but they are gone now."

"Do they often desert their towers?" Brion asked.

"Never. I have never heard of it happening before. I can think of
no reason why they should do a thing like this."

"Well, I can," Brion told him. "They would leave their home if they
took something with them of greater value. The bombs. If the bombs
were hidden here, they might move them after the attack." Sudden
fear hit him. "Or they might move them because it is time to take
them--to the launcher! Let's get out of here, the quickest way we
can."

"I smell air from outside," Ulv said, "coming from down there. This
cannot be, because the magter have no entrances this low in their
towers."

"We blasted one in earlier--that could be it. Can you find it?"

Moonlight shone ahead as they turned an angle of the corridor,
and stars were visible through the gaping opening in the wall.

"It looks bigger than it was," Brion said, "as if the magter had
enlarged it." He looked through and saw the tracks on the sand
outside. "As if they had enlarged it to bring something bulky up
from below--and carried it away in whatever made those tracks!"

Using the opening themselves, they ran back to the