History of the Peloponnesian War

By day it was thought impossible not to be discovered, either in their approach or in their ascent. Having therefore first commanded to take five days' provision of victual, and all the masons and workmen, as also store of casting weapons, and whatsoever they might need, if they overcame, for fortification, he and Eurymedon and Menander, with the whole army, marched about midnight to Epipolae, leaving Nicias in the camp.

Being come to Epipolae at Euryelus, where also the army went up before, they were not only not discovered by the Syracusians that kept the watch, but ascending took a certain fortification of the Syracusians there and killed part of them that kept it.