"Their flames went out utterly...night were the universe (p.282)." This represents the event in which he had swooned. This specific event relates to the theme despair. He passed out because of his inevitable sentence to death.
"My worst thoughts, then, were confirmed (283)." Be speaks about how alone he is in the torture chamber. He goes on to speak about how he struggled for breath. Also, how the darkness had began to stifle and oppress him. His despair had began to raise as he had felt hopeless.
"I struggled no more, but the agony of my soul found vent in one loud, long, and final scream of despair (p 292)." After trying, time after time, to escape the torture chamber, he had finally began to give up. He had accepted his fate with death. However, luckily, at the last minute General Lasalle had saved him.