Brennus, who seems to have had some military ability, seems to have become aware that the Ætolians made up the most numerous and effective part of the Greek army. He conceived the idea of detaching them by sending a force under his second-in-command to ravage Ætolia. The stratagem succeeded. The Ætolians, on hearing of the movement, hastened to march to the defence of their country. They were too late to save two of their frontier towns, which were stormed and sacked in the most brutal manner. But they were in time to exact a heavy vengeance from the barbarians. Of the fifty thousand who had been detached on this expedition, less than half returned to the camp at Thermopylæ. The incidents that followed bear a curious resemblance to the history of the first defence of Thermopylæ. The path by which the Persians, through the treachery of Ephialtes, were able to take the defenders of the pass in the rear was again used for the same purpose. The Phocian pickets were surprised as before, being hindered by the mist from seeing the Gauls till these were close upon them. But there was no obstinate determination among the Greeks to die upon the ground. They were carried off by the Athenian fleet, which from the first had been in attendance, keeping as close as possible to the shore. The object which now roused the cupidity of the barbarians was the shrine of Delphi with its treasury, still rich in the offerings of many generations of worshippers and inquirers, though it had not altogether escaped the hand of the spoiler.[32] As in the Persian war, the terrified inhabitants inquired of the god whether they should remove or conceal the sacred treasure. Again, as before, the answer was that the god would take care of his own. "I will provide, and with me the Maidens veiled in white," were the words of the oracle. The greater part of the army mustered at Thermopylæ had gone home; but there were some thousands who remained to protect Delphi. The god did not disdain to use their services, though the most effective protection came--so runs the story--from his own interference. The ground on which the Gauls had pitched their camp was shaken throughout the day by repeated shocks of earthquake, while overhead the thunder rolled and the lightning flashed incessantly. Through the darkened atmosphere might be seen the flashing arms of warriors who were more than mortal--one of them, it was said, the hero Pyrrhus, son of Achilles, who had met his death at Delphi many centuries before, and had ever since been worshipped as a local hero. That day, however, the Gauls held their own; many of the Phocians, in particular, were slain. But the night that followed was one of terrible suffering. A sharp frost set in, and following the frost came a heavy fall of snow. The snow symbolised "the maidens vested in white"--such, at least, was the rationalistic explanation given in after years. Nor was this all: great masses of