Antigonus, then, having got Acrocorinthus into his power, as I have said, kept it under guard, putting men there whom he most trusted, and making Persaeus the philosopher their commander. Now Aratus, even while Alexander was still living, had set his hand to the enterprise, but an alliance was made between the Achaeans and Alexander, and he therefore desisted.
At the time of which I speak, however, a new and fresh basis for the enterprise was found by him in the following circumstances.
There were in Corinth four brothers, Syrians by race, one of whom, Diodes by name, was serving as a mercenary soldier in the citadel. The other three, after stealing some gold plate of the king's, came to Aegias, a banker in Sicyon with whom Aratus did business. A portion of the gold they disposed of to him at once, but the remainder was being quietly exchanged by one of them, Erginus, in frequent visits.
Erginus thus became well acquainted with Aegias, and having been led by him into conversation about the garrison in the citadel, said that as he was going up to see his brother he had noticed in the face of the cliff a slanting fissure leading to where the wall of the citadel was at its lowest. Thereupon Aegias fell to jesting with him, and said:
‘Do you, then, best of men, thus for the sake of a little gold plate rifle the king's treasures, when it is in your power to sell a single hour's work for large sums of money? Don't you know that burglars as well as traitors, if they are caught, have only one death to die?’
Erginus burst out laughing, and as a first step agreed to make trial of Diodes (saying that he had no confidence at all in his other brothers), and a few days afterwards came back and bargained to conduct Aratus to the wall at a spot where it was not more than fifteen feet in height, and to aid in the rest of the enterprise together with Diodes.