Here's a snippet:
RFC: How do you determine that a series has run its course? Can you envision a series that could go on indefinitely that would still be fresh?
KB: Well, that's a tough one, my own 2 series, Brant, the very last one is AMMUNITION, OUT IN JULY FROM SMP and Jack Taylor, I'm working on no 7......... also the end......... I want them to end on a blast and a What if.
John Sandford, Larry Gough seem to be able to keep their series up to 17, 18, etc......... me, I'D GO MAD