s it."

They stared at him. "What do you mean?"

"It fires itself."

They couldn't believe him. Nasha came close to him, frowning, looking up
at him. "I don't understand. What do you mean, it fires itself?"

"Watch, I'll show you. Don't move." Dorle picked up a rock from the
ground. He hesitated a moment and then tossed the rock high in the air.
The rock passed in front of the gun. Instantly the great barrel moved,
the vanes contracted.

* * * * *

The rock fell to the ground. The gun paused, then resumed its calm
swivel, its slow circling.

"You see," Dorle said, "it noticed the rock, as soon as I threw it up in
the air. It's alert to anything that flies or moves above the ground
level. Probably it detected us as soon as we entered the gravitational
field of the planet. It probably had a bead on us from the start. We
don't have a chance. It knows all about the ship. It's just waiting for
us to take off again."

"I understand about the rock," Nasha said, nodding. "The gun noticed it,
but not us, since we're on the ground, not above. It's only designed to
combat objects in the sky. The ship is safe until it takes off again,
then the end will come."

"But what's this gun for?" Tance put in. "There's no one alive here.
Everyone is dead."

"It's a machine," Dorle said. "A machine that was made to do a job. And
it's doing the job. How it survived the blast I don't know. On it goes,
waiting for the enemy. Probably they came by air in some sort of
projectiles."

"The enemy," Nasha said. "Their own race. It is hard to believe that
they really bombed themselves, fired at themselves."

"Well, it's over with. Except right here, where we're standing. This one
gun, still alert, ready to kill. It'll go on until it wears out."

"And by that time we'll be dead," Nasha said bitterly.

"There must have been hundreds of guns like this," Dorle murmured. "They
must have been used to the sight, guns, weapons, uniforms. Probably they
accepted it as a natural thing, part of their lives, like eating and
sleeping. An institution, like the church and the state. Men trained to
fight, to lead armies, a regular profession. Honored, respected."

Tance was walking slowly toward the gun, peering nearsightedly up at it.
"Quite complex, isn't it? All those vanes and tubes. I suppose this is
some sort of a telescopic sight." His gloved hand touched the end of a
long tube.

Instantly the gun shifted, the