This section of the short story comes towards its denouement, as the storm that clearly symbolises the intense agitation inside Roderick himself reaches its height as does Roderick's nervous agitation. Desperate to try and do something to calm Roderick down and take his mind off the storm, which is clearly causing such bizarre behaviour, the narrator takes what he calls one of Roderick's "favourite books" and begins to read it to him in an attempt to calm him down. Note what the narrator says of this choice:
The antique volume which I had taken up was the "Mad Trist" of Sir Launcelot Canning; but I had called it a favourites of Usher's more in sad jest than in earnest; for, in truth, there is little in its uncouth and unimaginative prolixity which could have had interest for the lofty and spiritual ideality of my friend. It was, however, the only book immediately at hand; and I indulged a vague hope that the excitement which now agitated the hypochondriac, might find relief... even in the extremeness of the folly which I should read.
What is ironic however about his reading choice is that the content of the passage he is reading, where Ethelred gains admission into a building by force, is about to be acted out in the most terrifying way by Madeline herself, causing Roderick even greater suffering.