Titus Livius (Livy), The History of Rome, Book 9
Benjamin Oliver Foster, Ph.D., Ed.

25. The consuls on leaving Sora conducted a campaign against the lands and cities of the Ausones.¹ [2] for everything had been disturbed by the coming of the Samnites, when the battle was fought at Lautulae, and conspiracies had been formed all about Campania. even Capua itself did not escape accusation; nay, the investigation actually led to Rome and to some of the prominent men there. [3] but the Ausones were brought into subjection by the betrayal of their cities, as had happened in the case of Sora. [4] from Ausona,² from Minturnae, and from Vescia, twelve young nobles, having conspired to betray their cities, came to the consuls, and explained to them that their countrymen, after long looking forward to the coming of the Samnites, had no sooner heard of the [5??] battle at Lautulae than they had concluded the Romans vanquished and had aided the Samnites with men and arms; [6] that since the expulsion of the Samnites from that region, they had been living in an uncertain kind of peace, not closing their gates upon the Romans, lest to do so should invite attack, but determined none the less to close them in case an army should approach; and that in that wavering state of mind they could be surprised and overcome. [7] by their advice the camp was moved up nearer and soldiers were simultaneously sent round to the three towns. some of these, in armour, were to lie in ambush in places near the walls, while others, wearing the toga and concealing swords under their dress, were to enter the cities, a little before day, by the open gates. [8] [p. 261]These latter fell upon the watchmen, at the same³ time making a signal to their fellows in armour to rush in from their ambuscade. thus the gates were captured, and three towns were taken in one hour and by one device. [9] but because the leaders were not present when the attack was made, there was no limit to the slaughter, and the Ausonian nation was wiped out —though it was not quite clear that it was guilty of defection —exactly as if it had contended in an internecine war.