"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." The Mayor of Steadheim considered this information. "_Ha-hmmm!_" he said profoundly. "Criminals can be kept down, but a revolt can't be suppressed," Kim went on. "The soldiers who are occupying the twenty-one planets will be called back to put down revolts, as soon as the people discover the Disciplinary Circuits on their planets are blowing out, and that they blow out again as fast as they're re-made and used." "_Hm!_" said the Mayor of Steadheim. "Not bad! And the rebels will have some very tasty ideas of what to do to the folk who've tyrannized over them. No troops can stop a revolt nowadays. Not for long!" "No, not for long," said Kim. "No government will be able to rule with a dissatisfied population. Not if it has a little gadget hidden somewhere that will blow out the Disciplinary Circuit, if it's used to excess." "Good enough, good enough," grumbled the mayor. "When rulers are kept busy satisfying their people, they won't have time to bother political offenders. That's sensible enough! But it's too fiendish bad that only those twenty planets have the gadgets on them! I suppose we criminals will have to set up a factory and make them, and then visit all the three hundred million inhabited planets, one by one, and drop one little contrivance on every one. But it'll take us centuries! Space! That's a pity!"