Why NOT write them? The connected series is a staple of most genre fiction. Mystery series have abounded for decades, as have fantasy and science fiction series, but only in the last fifteen years has the romance series become popular. At the beginning, they were rare. When an author did write them, as with Johanna Lindsey’s Malory series, they weren’t necessarily planned out ahead, the way they are now, with publishers announcing the series connections from the beginning. More often, authors wrote isolated connected books here and there, like Jayne Ann Krentz’s Gift of Gold and Gift of Fire (two of my all-time favorites). Eventually the romantic series came into its own, and now authors write them more often than not. My own School for Heiresses series, Regency-set historicals featuring the spirited graduates of Mrs. Harris’s School for Young Ladies, is the fourth series I’ve written. These unconventional heiresses who prove a match for society’s most irresistible rogues are connected only by their association with the school, but I’ve also written series where the characters were friends, royal half-brothers, and sisters. Here’s why I like writing them: The over-arching themes—in this particular series I include a running thread in the…