Kim told him, as well as he could. The Mayor of Steadheim fumed.
"Took over the twenty-one planets, eh?" he sputtered. "We'll attend to that. We'll take a few ships, go over there, and punish 'em."
"I suspect they've pulled out," said Kim. "If they haven't, they will. And soon! The Gracious Majesties and Magnificents, and the other planetary rulers who essayed some easy conquests, have other need for their soldiers now. Plenty of need!"
"Eh, what?" cried the mayor. "What's the matter? Those rulers have got to have a lesson! We didn't try to free the whole Galaxy because it was too big a job. But it looks like we'll have to try!"
"I doubt the need," said Kim, amused. "After all, it's the Disciplinary Circuit which has enslaved the human race. When the psychogram of every citizen is on file, and a disciplinarian has only to put his card in the machinery and press a button to have that man searched out by Disciplinary-Circuit waves and tortured, wherever he may be—when that's possible—any government is absolute. Men can't revolt when the whole population or any part of it can be tortured at the ruler's whim."
Dona's expression changed.
"Kim!" she said accusingly. "Those things you got on Spicus Five and dropped on the planets the soldiers came from—what were they?"
"I'll tell you," said Kim. "The Disciplinary Circuit is all right to keep criminals in hand—not rebels like us, but thieves and such—and it does keep down the number of officials who have to be supported by the state. Police and guards aren't really needed on a free planet with the Disciplinary Circuit in action. It's a useful machine for the protection of law and order. The trouble is that, like all machines, its use has been abused. Now it serves tyranny. So I made a device to defend freedom."
The Mayor of Steadheim cocked a suspicious eye upon him.
"I procured a little gadget," said Kim. "I dropped the gadget in various places where it wasn't likely to be found. If one man is under Disciplinary Circuit punishment, or two or three or four—that's not unreasonable on a great planet—nothing happens. But if twenty-five or fifty or a hundred are punished at once, the Disciplinary Circuit is blown out as I just blew out that force-field generator."