From Decorator to Teacher in 5 short years

I was talking to a writer friend about how to know when to end a series. I immediately flashed back to 2015, after WITH VICS YOU GET EGGROLL, the third in the Madison Night Mystery Series. I remember being at a conference and chatting with a (different) writer friend (writers tend to have lots of writer friends, mostly because we understand things like the lure of internet card games and a never-ending fascination with our Amazon rank) who asked when book four would come out. I told her I didn’t know if I was going to write a book four; I might let the series stand at three.

She seemed surprised. Was I out of ideas? Had I