** spoiler alert **
If it weren't for this book, I'd be a bit more pleased with the overall ending of the series.
I just didn't like how the last letter in The Beatrice Letters was so CONFUSING to me! I couldn't figure out what the heck Lemony Snicket was doing. I know he never gives straight answers, but he could've... alluded to finally agreeing to meet the other Beatrice and helping her track down her family. I don't need every answer to every question, but I do like some resolution, and I feel like that book made the end of the series really uneasy for me. So basically we're left to understand that the Baudelaires raised the other Beatrice, and then all of a sudden they disappeared. He could've left us with some unanswered questions, but at least something like "and then Lemony and Beatrice went to go find them." We don't have to be told that they're reunited or anything, but just... something!
Perhaps we're only meant to know that the second Beatrice goes on to have unfortunate events of her own, and I think that's a great way to do it. But I don't think I'm really okay with suddenly having the three Baudelaires disappear, which no clue as to what happened. We were not meant to know what happened to the second Beatrice, and yet we're sort of entitled to receive some sort of conclusion to the Baudelaires' story. They wouldn't necessarily have had a happily ever after, after the events of The End, but just a quiet, normal life together would have made sense to me. Particularly after the point that Lemony Snicket kept on making about "This is where their story concludes." It isn't quite fair to allude to them having yet more unfortunate events (I mean, they disappeared! That's pretty unfortunate) and us not getting to hear about them because Snicket didn't go document them.