t we need a _Thor_ gun?" Susan Sidwell
said. Susan had majored in ionic chemistry and had graduated with high
honors.

"No, it isn't dangerous at all," the instructor answered hastily. "The
weapon is worn merely for the sake of tradition."

"No danger at all, young lady," the captain said. "Nothing to worry
about. Not while you've got this, anyhow." He patted the _Thor_ gun
which the instructor was buckling to his waist.

The gates were open. The instructor in the lead, the group passed
through. Billy Kasker brought up the rear. Joe Buckner was directly
ahead of him.

They went first to see the wreckage of the city--shattered walls,
tumbled buildings, streets with rubble still piled in them. Weeds and
creeping vines grew over the broken bones of this city as if they were
attempting to hide the ugly scars.

The instructor adjusted his voice to the proper tone. He had made this
same speech to many graduating classes and he knew exactly what he was
going to say.

"You understand, of course, that this part of the old city was almost
completely destroyed in our attack of the year 4021 After Yevbro, or the
year 1967, according to the way the natives reckoned time on this
planet. This part of it has been allowed to remain the way our ships
left it, as an example of the effectiveness of our weapons."

His voice gave the impression that he was personally participating in
that attack and was enjoying the destruction that had taken place. He
stood straight, squared his shoulders and breathed deeply.

"What happened to the natives who lived here?" Billy Kasker asked.

The instructor frowned. "Oh, they were killed." At first he was a little
irritated at the question, then again satisfaction came back into his
voice.

"They got what was coming to them for trying to resist our sky ships,"
Joe Buckner said.

"Oh, yes, they deserved their fate." The instructor hitched the _Thor_
gun a little higher on his hip.

Billy Kasker was silent.

"We will go next to the fields, then to the factory section--such of as
there is--then to that part of the city which we have allowed the
natives to rebuild. Come."

The class moved out of the city. Here they saw their first natives. Clad
mostly in rags--many of them bent and stooped, some of them showing the
marks of hunger--they were a quiet people who kept strictly out of the
way of the class group. But except for the clothing and the marks of
hunger, they were identical in appearan