Should I still read the book?

I am reading an 800-page book. It's called The Mitfords  and is a collection of letters sent between the 6 infamous sisters over many, many decades. 

Simon loves 800-page books, just as a general rule.

Recently, he picked up my book and flipped through it.

He hands it back to me: "Just so you know, A few of the sisters die at the end, and the whole family falls apart."