A Question From My Agent

Last week my agent posted on his blog about "series death", including this question:

What can you as a writer do to hold onto that “core value” of a series?

 Series Death is a thing I think a lot about, especially since I do have a Long Term Plan.  The last thing I want is to drag things on past their sell-by date, or reach the point where I'm just painting in the numbers.  Or, worst of all in my opinion, where I'm just spinning my wheel, filling pages with "nothing happened". 

Two big things causes Series Death, in my opinion:
1. When the writer shifts from being hungry, eager to keep outdoing themselves,  to being lazy, cranking out more books for the sake of more books.
2. Connected to that, when the writer ceases seeing an end-goal for the series, and thus is forever shuffling the board instead of playing for the win.

So what can I do? (Besides the fact that my agent, saints willing, will keep my feet to the fire and not let me get lazy about these things?) 
The big one, for me, will be keeping my eye on the second one.  A series needs a good ending, and it needs to move towards that with every installment.  If the whole series is a journey from Point A to Point Z, every book in the series needs to make significant progress in that journey.  Some series end up dithering around Point Q or R, not sure how to pace out the final journey, since they don't know how many books they're going to write.

Can we raise a small glass to J.K. Rowling, who could have EASILY gone, "I think I'll make this nine or ten books" and dragged things out.  Instead, she planned it at seven, and kept it there.

And that's how you avoid it dying on you: By ending it intentionally. 

Which, according the the Big Crazy Plan, is exactly what I intend to do.