XIII. When Antiochus occupied the pass of Thermopylæ with his army, and, after adding to the natural strength of the place by artificial defences, established himself there as if in an impregnable position, the Romans decided that to attack him in front was altogether impossible, but Cato, remembering how the Persians under Xerxes had turned the Greek forces by a circuitous march over the mountains, took a part of the force and set off by night. When they had gone for some distance over the mountains, the prisoner who served as their guide lost his way, and wandered about in that precipitous and pathless wilderness so as to cause great discouragement to the soldiers. Seeing this, Cato ordered every one to halt and await his orders, and himself, with one companion, one Lucius Manlius, an experienced mountaineer, laboriously and daringly plunged along through intense darkness, for there was no moon, while the trees and rocks added to their difficulties by preventing their seeing distinctly whither they were going, until they came to a path, which, as they thought, led directly down upon the camp of the enemy. Hereupon they set up marks to guide them upon some conspicuous crags of Mount Kallidromus, and returning to the army, led it to these marks, and started along the paths which they had descried. But before they had proceeded far the path ended in a precipice, at which they were both surprised and disheartened; for they could not tell, either by sight or hearing, that they were close to the enemy. It was now about daybreak, and they thought that they heard voices near at hand, and soon were able to see a Greek camp and an outpost at the foot of the precipice. Cato hereupon halted his army, and ordered the Firmiani,[30] in whom he reposed especial confidence, to come forward alone. When they had assembled round him, he said, "I wish to take one of the enemy prisoner, and learn from him of what troops this outpost is formed, what their numbers are, how the rest of the army are placed, and what preparations they have made to resist us. You must dash upon them as quickly and boldly as lions do upon their defenceless prey." At these words of Cato's the Firmiani at once rushed down and attacked the outpost. The suddenness of their onset threw the enemy into complete confusion, and they soon caught one of them and brought him before Cato. Learning from this man that all the rest of the army was with King Antiochus himself, guarding the pass of Thermopylæ, and that only a body of six hundred picked Ætolians were watching the path over the mountains, Cato despising so small and contemptible a force, at once drew his sword, and led on his troops with shouts and trumpets sounding the charge. The Ætolians, as soon as they saw the Romans descending from the hills, fled to the main body, and filled it with confusion and terror.