Our book club picked a 500 page sci-fi epic and only two people finished it before the meeting.

We voted on it last month and everyone seemed excited. The meeting was yesterday and it was just me and Sarah who had read the whole thing. The rest said they got lost in the world building around page 200. We spent the whole hour just trying to explain the plot instead of debating the themes. Has your group ever picked a book that was just too big for most people to finish in time? How do you handle it?