Read the excerpt from Poe’s "The Fall of the House of Usher."

I say that even their exceeding density did not prevent our perceiving this -- yet we had no glimpse of the moon or stars -- nor was there any flashing forth of the lightning. But the under surfaces of the huge masses of agitated vapour, as well as all terrestrial objects immediately around us, were glowing in the unnatural light of a faintly luminous and distinctly visible gaseous exhalation which hung about and enshrouded the mansion.
Which statement best describes the effect of the narration on the story?