Edger allen poe's fall of the house of usher. what does the narrator discover, rather abruptly? that roderick is playing a prank on him. that roderick actually hates the books they are reading that madeline is dead that the house is falling apart

The narrator discovers, rather abruptly, that Madeline is dead.

That Madeline is dead

Explanation:

He clearly states that he has been informed of Madeline Usher's fate abruptly as you can read yourself taken directly from "Fall of the house of Usher" as it follows:

"I could not help thinking of the wild ritual of this work, and of its probable influence upon the hypochondriac, when, one evening, having informed me abruptly that the lady Madeline was no more,"