It seems to have added very much to the interest of an historical narrative in the minds of the ancient Greeks, to have some prodigy connected with every great event; and, in order to gratify this feeling, the writers appear in some instances to have fabricated a prodigy for the occasion, and in others to have elevated some unusual, though by no means supernatural circumstance, to the rank and importance of one. The prodigy connected with this siege of Babylon was the foaling of a mule. The mule belonged to a general in the army of Darius, named Zopyrus. It was after Darius had been prosecuting the siege of the city for a year and a half, without any progress whatever toward the accomplishment of his end. The army began to despair of success. Zopyrus, with the rest, was expecting that the siege would be indefinitely prolonged, or, perhaps, absolutely abandoned, when his attention was strongly attracted to the phenomenon which had happened in respect to the mule. He remembered the taunt of the Babylonian on the wall, and it seemed to him that the whole occurrence portended that the time had now arrived when some way might be devised for the capture of the city. Portents and prophecies are often the causes of their own fulfillment, and this portent led Zopyrus to endeavor to devise some means to accomplish the end in view. He went first, however, to Darius, to converse with him upon the subject, with a view of ascertaining how far he was really desirous of bringing the siege to a termination. He wished to know whether the object was of sufficient importance in Darius's mind to warrant any great sacrifice on his own part to effect it. He found that it was so. Darius was extremely impatient to end the siege and to capture the city; and Zopyrus saw at once that, if he could in any way be the means of accomplishing the work, he should entitle himself, in the highest possible degree, to the gratitude of the king. He determined to go himself into Babylon as a pretended deserter from Darius, with a view to obtaining an influence and a command within the city, which should enable him afterward to deliver it up to the besiegers; and, in order to convince the Babylonians that his desertion was real, he resolved to mutilate himself in a manner so dreadful as would effectually prevent their imagining that the injuries which he suffered were inflicted by any contrivance of his own. He accordingly cut off his hair and his ears, and mutilated his face in a manner too shocking to be here detailed, inflicting injuries which could never be repaired. He caused himself to be scourged, also, until his whole body was covered with cuts and contusions. He then went, wounded and bleeding as he was, into the presence of Darius, to make known his plans.