Well, I've been having some trouble working on my sequel to THE GUARDIAN lately. Last night, I got into a big discussion about some of my ideas for it with my wife (I keep telling you, she's a terrific editor, etc), and I basically came to realize that I was (again) heading down the wrong path with the plot of this book.
I have a number of possible plots for use in the series (which is intended to be seven books), and though I know the overarching story and themes that I want to cover in each installment, the specifics of the sub-plots and smaller-scale events are not mapped out. I think that this is pretty common; it gives my entire series room to grow in unexpected directions, etc.
Well, anyway, this is the second time that I've scrapped a large chunk of this second book, and gone back to start writing it again. This time I'm pretty confident that I have it right, though--the solution that was found last night is actually kind of obvious: write a closer continuation of the first story, which is what I had intended to do from the start, rather than trying to branch off in too many other directions at once (with the sub-plots, that is). See, THE GUARDIAN is a complete book by itself (as it has to be, of course), but it also leaves a number of things open, or in progress, at the very end. In other words, its strongest sub-plot is resolved to satisfaction, but all the secondary sub-plots continue. This was by design, and is just part of how one sets out to write a series, in my mind--there are a lot of single-books-that-turn-into-trilogies that don't do this, but that generally makes for a jarring leap between books 1 and 2. And even those trilogies tend to do this between books 2 and 3.
My whole goal with the way I ended the first book was to avoid that problem in the transition between the first and second book, but somehow when I started working on the sequel I still ignored a lot of that. The problem, then, became that the sequel was just feeling too separate to me. Each book in a series needs to be its own individual story, but the books all need to be connected in numerous ways, too. It's when those connections start feeling too tenuous that readers get irritated and drop the series (there are other reasons too, of course, but that's a big one).
Sequel-writing has a lot of challenges to it that simply do not exist in writing a first book, or a standalone book. I've broached the topic a little bit today, but expect to see a lot more on this subject in the future. This is a particularly interesting subject to me, both because that's what I am currently trying to write, and because it's something that is discussed so much less among writers. I think that the general sense among a lot of people is that if you can author one book, authoring the followup is much easier. There are a few senses in which that is true, but a vast many more in which that is a horrible lie: the bar is set that much higher in every installment in a series, and it's the writers who understand that who write the really stellar series.