History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
The generals accordingly conveyed the men under truce to the island of Ptychia[*](cf. iii. lxxv. 5; now called Vido.) to be kept under custody there until they should be sent to Athens, and the understanding was that if anyone should be caught trying to run away the truce should be regarded as broken for them all.
But the leaders of the popular party at Corcyra were afraid that the Athenians would not put them to death on their arrival at Athens, and therefore resorted to the following stratagem.
They first tried to persuade a few of the men on the island to run away, by secretly sending thither friends who were instructed to say, with a show of good will, that the best course for them was to do this with no loss of time, and promising to have a boat ready; for the Athenian generals, they explained, were intending to deliver them up to the Corcyraean populace.