Having finished the wall of palisades by which the town was completely cut off from the land, he recrossed the Bosporos, with such troops as could be spared from the siege of Chalkedôn, to raise contributions for the war. At Selymbria, a Greek town on the Thrakian coast of the Propontis, he was called upon once more to prove his fearless intrepidity, his calmness and resource in the midst of danger, and his gentleness in the hour of victory. He arrived before the town with a body of his own hoplites and his Thrakian horsemen. Some of the citizens were willing to ally themselves with Athens, or rather, perhaps, were unwilling to struggle against one who seemed to be invincible. They agreed to open the gates to him at midnight, and promised to display a lighted torch upon the walls as a signal that they were ready to receive him. One of them betrayed the design to the authorities of Selymbria. The others, fearing the vengeance of the citizens, showed the signal from the walls an hour before the appointed time, and opened the city gates. Alkibiades, who had given orders for the main body of his men to be ready to enter the town with him at midnight, on seeing the signal, though his men were not yet ready, rushed to the open gate, followed by only thirty of his guard. He was joined by twenty of those who were friendly to him within the town. With this handful of followers he found himself in the narrow streets and in the midst of an angry multitude. Here again he was in imminent peril of his life. He refused to retreat, although he could not hope that thirty men, however brave, assisted by only twenty citizens, could hold their ground until his hoplites and his Thrakians should come to his aid. He ordered a trumpet to be sounded, and as calmly as if he was at the head of a victorious army, he made a proclamation ‘that the Selymbrians would incur the anger of the state of Athens if they dared to take up arms against the Athenians.’ His extraordinary coolness so frightened the people, who supposed a proclamation such as this would never have been made unless the whole army was behind him and entering the city, that they asked for conditions. While these were being arranged the rest of his army entered. Selymbria was now at his mercy. According to the rights or wrongs of war, he might have robbed it of its riches and allowed the outrage of its citizens. He forbade both, and risked the anger of his half-tamed Thrakians, who could not understand how a hostile city could be taken without the necessary consequence of rapine, by sending them out of Selymbria baulked of their prey. Taking only a reasonable sum of money by way of tribute, he left a garrison behind to protect Selymbria from the Spartans.