Rocco refused point blank to do the horrid deed; but as a dependent he could not control matters, and hence he had to consent to dig the grave, with the understanding that Pizarro, himself, should do the killing.

Thus far, Fidelio had been able to find out nothing about her beloved husband, but she had become more and more of a favourite with the unfortunate old jailer, and was permitted to go about with a certain amount of freedom.

Upon the day when Pizarro had directed Rocco to kill a prisoner in a certain dungeon, she overheard a good deal of the plot, and she began to fear it might be her husband.

She went at once to Rocco:

"Rocco, I have seen very little of the prison. May I not go into the dungeon and look about?"

"Oh, it would never be allowed," Rocco declared. "Pizarro is a stern and cruel governor, and if I should do the least thing he did not command, it would go hard with me. I should not dare let you do that," he said, much troubled with the deed that was in hand.

"But wilt thou not ask him, Rocco?" Fidelio entreated so determinedly that Rocco half promised.

"Fidelio, I will tell thee. I have a bad job to do. It is to dig a grave in one of the dungeons." Fidelio could hardly conceal her horror and despair. Her suspicions were confirmed. "There is an old well, covered by a stone, down there, far underground, and if I lift the stone that covers it, that will do for the grave. I will ask Pizarro if I may have thee to help me. If he consents, it will be thy chance to see the dungeons, but if not, I shall have done all I can about it." So he went away to discuss the matter with Pizarro, while Fidelio waited between hope and despair.

Meantime, Pizarro was gloating over his triumph. Soon his revenge would be complete, and he sang of the matter in a most savage fashion:

Ha! what a day is this,
My vengeance shall be sated.
Thou treadest on an abyss!
For now thy doom is fated.