Instead of answering the question, the Director rose and walked across the room to a row of hermetically sealed cases. Like the display units in small and dusty museums, these held a few yellowed books, chunks of unclassified rock, and an occasional fossil. But one of them was broken.
"This case," said the Director, "once held an obscure book by a Twentieth Century warlord. Know the period?"
"I'm a mechanic," said Timmy.
"Most of us are these days. It's something of a pity. But in the middle Twentieth Century, historians tell us of a semi-civilized chieftain named Hetlir, or Schicklegrub, who managed to control the mass of Europa through an intelligent but utterly unscrupulous plan. The seeds of that plan lie in a book called Mein Kampst ... and this case once held a copy."
"I see," said Timmy, but he didn't.
"Two years ago," continued the Director, "I entertained a leader of the Neptunian Tsom clan. When he left, the book went with him."
"How can a book affect us?"
"Easily. Our only defense against the powerful semi-humans of Neptune has been their own inability to organize any planetary unity. They trade with us on a basis of toleration ... but they're not friends."
"Why haven't they attacked before?"
"Their clan system, and their wars at home."