The summer was now drawing to a close, and as yet no progress had been made with the siege of Mytilene. The town was still blockaded by sea, but the Mytilenaeans had free egress on the land-side, and marched up and down the island, confirming the other towns which had joined in the revolt, and threatening Methymna, which still remained loyal to the Athenian alliance. When the Athenians were informed of this state of things, they sent a thousand hoplites under Paches to reinforce the besieging army; and on their arrival the investment of Mytilene was completed by a wall drawn from sea to sea, and cutting off the town from the rest of the island. The Mytilenaeans now began to despair, for their supplies were failing, and there seemed no hope of relief. But during the winter a ray of hope reached them from outside, and encouraged them to persevere in their resistance. There was a weak point in the Athenian wall, where it closed a ravine; and through this interval a Spartan named Salaethus, who had sailed to Lesbos in a trireme, and crossed the island on foot, succeeded in making his way into the town. Salaethus announced himself as an agent sent from Sparta, to inform the distressed garrison that, as soon as the season permitted, forty triremes would be sent to their assistance, and that Attica would be invaded at the same time, to keep the enemy occupied at home. At this welcome news the hopes of the Mytilenaeans revived, and all thoughts of surrender were laid aside.
As soon as spring arrived, the Spartans, true to their promise, sent off forty triremes, commanded by Alcidas, to raise the siege of Mytilene, and marched in full force into Attica, thinking thus to divert the attention of the Athenians, and prevent them from interfering with the voyage of Alcidas. They remained a long time in Attica, waiting for news from their fleet, and employing the time in a systematic ravage of the whole territory. But time passed, and no message arrived from Alcidas, who seemed to have disappeared with all his ships; so that at last, as their expectations were disappointed, and their supplies exhausted, they broke up their army and returned home.
The position of Mytilene was now growing desperate. Nothing more was heard of the relieving squadron, and the scanty store of provisions was rapidly failing; for, owing to the betrayal of their design, the Mytilenaeans had been hurried into revolt before their preparations were completed, and had had no time to lay up a sufficient stock of food. Salaethus, therefore, determined to make a sudden sally, and break out of the town; and the better to effect this purpose, he furnished the common people, who had hitherto served as light-armed soldiers, with the full equipment of heavy infantry. But this proceeding brought on a catastrophe, for the commons no sooner found themselves in possession of better weapons than they turned upon their masters, and accused them of secreting supplies of corn for their own use. "Bring out your corn," they cried, "and divide it equally, or we will go out and make terms with the Athenians for ourselves." Alarmed at this threat, which if carried out would leave them exposed as the sole objects of Athenian vengeance, the nobles sent a message to Paches, on behalf of the whole city, offering to surrender, on condition that their case should be tried by the tribunals at Athens, and stipulating that, while the decision was pending, no violence should be offered to any of the inhabitants. The proposal was accepted, and Paches marched his forces into the town. In spite of the convention, the leaders of the revolt took sanctuary in the temples, being in dread of summary execution. Paches reassured them, and sent them in safe custody to Tenedos.