After these came another party of light troops armed with spears, whose shields, that they might advance the easier, were carried by men behind, who were to hand them to them when they found themselves in presence of the enemy. After a good many had mounted they were discovered by the sentinels in the towers, by the noise made by a tile which was knocked down by one of the Plataeans as he was laying hold of the battlements. The alarm was instantly given, and the troops rushed to the wall, not knowing the nature of the danger, owing to the dark night and stormy weather; the Plataeans in the town having also chosen that moment to make a sortie against the wall of the Peloponnesians upon the side opposite to that on which their men were getting over, in order to divert the attention of the besiegers. Accordingly they remained distracted at their several posts, without any venturing to stir to give help from his own station, and at a loss to guess what was going on. Meanwhile the three hundred set aside for service on emergencies went outside the wall in the direction of the alarm. Fire-signals of an attack were also raised towards Thebes; but the Plataeans in the town at once displayed a number of others, prepared beforehand for this very purpose, in order to render the enemy's signals unintelligible, and to prevent his friends getting a true idea of what was passing and coming to his aid before their comrades who had gone out should have made good their escape and be in safety.
Meanwhile the first of the scaling party that had got up, after carrying both the towers and putting the sentinels to the sword, posted themselves inside to prevent any one coming through against them; and rearing ladders from the wall, sent several men up on the towers, and from their summit and base kept in check all of the enemy that came up, with their missiles, while their main body planted a number of ladders against the wall, and knocking down the battlements, passed over between the towers; each as soon as he had got over taking up his station at the edge of the ditch, and plying from thence with arrows and darts any who came along the wall to stop the passage of his comrades. When all were over, the party on the towers came down, the last of them not without difficulty, and proceeded to the ditch, just as the three hundred came up carrying torches. The Plataeans, standing on the edge of the ditch in the dark, had a good view of their opponents, and discharged their arrows and darts upon the unarmed parts of their bodies, while they themselves could not be so well seen in the obscurity for the torches; and thus even the last of them got over the ditch, though not without effort and difficulty; as ice had formed in it, not strong enough to walk upon, but of that watery kind which generally comes with a wind more east than north, and the snow which this wind had caused to fall during the night had made the water in the ditch rise, so. that they could scarcely breast it as they crossed. However, it was mainly the violence of the storm that enabled them to effect their escape at all.
Starting from the ditch, the Plataeans went all together along the road leading to Thebes, keeping the chapel of the hero Androcrates upon their right; considering that the last road which the Peloponnesians would suspect them of having taken would be that towards their enemies' country. Indeed they could see them pursuing with torches upon the Athens road towards Cithaeron and Druoskephalai or Oakheads. After going for rather more than half a mile upon the road to Thebes, the Plataeans turned off and took that leading to the mountain, to Erythrae and Hysiae, and reaching the hills, made good their escape to Athens, two hundred and twelve men in all; some of their number having turned back into the town before getting over the wall, and one archer having been taken prisoner at the outer ditch. Meanwhile the Peloponnesians gave up the pursuit and returned to their posts; and the Plataeans in the town, knowing nothing of what had passed, and informed by those who had turned back that not a man had escaped, sent out a herald as soon as it was day to make a truce for the recovery of the dead bodies, and then, learning the truth, desisted. In this way the Plataean party got over and were saved.
Towards the close of the same winter, Salaethus, a Lacedaemonian, was sent out in a galley from Lacedaemon to Mitylene. Going by sea to Pyrrha, and from thence overland, he passed along the bed of a torrent, where the line of circumvallation was passable, and thus entering unperceived into Mitylene told the magistrates that Attica would certainly be invaded, and the forty ships destined to relieve them arrive, and that he had been sent on to announce this and to superintend matters generally. The Mitylenians upon this took courage, and laid aside the idea of treating with the Athenians; and now this winter ended, and with it ended the fourth year of the war of which Thucydides was the historian.