History of the Peloponnesian War

The Athenians, after plans had been arranged between themselves and their correspondents both as to words and actions, sailed by night to Minoa, the island off Megara, with six hundred heavy infantry under the command of Hippocrates, and took post in a quarry not far off, out of which bricks used to be taken for the walls;

while Demosthenes, the other commander, with a detachment of Plataean light troops and another of Peripoli, placed himself in ambush in the precinct of Enyalius, which was still nearer. No one knew of it, except those whose business it was to know that night.

A little before daybreak, the traitors in Megara began to act. Every night for a long time back, under pretence of marauding, in order to have a means of opening the gates, they had been used, with the consent of the officer in command, to carry by night a sculling boat upon a cart along the ditch to the sea, and so to sail out, bringing it back again before day upon the cart, and taking it within the wall through the gates, in order, as they pretended, to baffle the Athenian blockade at Minoa, there being no boat to be seen in the harbour.