Over the course of the past few months, I have read a number of books that were parts of a trilogy. Specifically, the first and second books. In both cases (I'm not going to name the series, but if you want to hunt around Goodreads and find the reviews, go ahead) the first book in the series blew me away. It was a great read, fantastic storytelling, original concepts, etc. Everything you could hope for in a book, particularly when in both cases these were the first books by those authors that I had read. In one case, it was the first book by that author (though the author was working in collaboration with another, more established author). Things were good.
Then I read the second book, and things became less good.
Some of this is simply a case of expectations. As a reader, if the first book is good, I expect the rest to be. After all, if the author did it once, they should be able to do it again. (Presumably. The writing profession has it's share of one-hit wonders, too.) I don't expect to always like every book an author puts out - though I hope to - but that's okay. Everyone has off moments. What I do expect is that if an author takes the time to plan a trilogy, then they've put the time in to think it through and carefully craft it. Such is not always the case, but such are my expectations.
Also, having started with such a phenomenal book, there is probably pressure on the author much the same as pressure is put on a successful film when it moves into sequel territory. The need to go bigger, or more complex, or to in some ways shake things up because the first one broke so much new ground that it's impossible to follow it otherwise. Or they go in the other direction, and the sequel is a formulaic copy of the first.
That happens, too, but for both of the series I read it was more the first trap. Nor did it work out well for either series. The first series introduced an essentially useless macguffin in the second book that opened up massive plot holes and seemed a sad throwaway device. The second series padded out the center section of the second novel by adding in police procedural details that were at worst wholly unnecessary to the plot and at best could have been dealt with in much shorter passages.
Nor is this the first year this has happened with books I've read. I really enjoyed the first volume of Dean Koontz's Frankenstein series. The second book was not only disappointing but downright silly. Enjoyable, but at nowhere near the level of the first one.
All of which is a roundabout way for me to make the following plea: Authors, if you're going to write a trilogy, and the first one gets really good reviews and press, please, please, PLEASE, do not f*** up the rest of them.
I don't think that's too much to ask.