Read it through once

"You must not--you shall not behold this!" said I, shudderingly, to Usher, as I led him, with a gentle violence, from the window to a seat. "These appearances, which bewilder you, are merely electrical phenomena not uncommon--or it may be that they have their ghastly origin in the rank miasma of the tarn. Let us close this casement;--the air is chilling and dangerous to your frame. Here is one of your favourite romances. I will read, and you shall listen;--and so we will pass away this terrible night together."