The battle with the Orc is borrowed from the tale of Perseus.
One merely gathers, that Orc releases himself in order to marry the shadowy daughter of Urthona,—Ah!
The prelude is the lament of a nameless shadowy female, who rises from out the breast of Orc.
Orc is heard raging on Mount Atlas, where he is chained down with the chain of jealousy.
But with the dawn of that morning ...