Not until last weekend did I hear of the Twilight series. You know it? Twilight is the young-adult phenom that is the sagging book industry’s greatest hope since Harry Potter. The last in the three-year-old, four-book series, Breaking Dawn, got a 3.2 million-book run. In the first 24 hours after its release last Saturday, Borders reportedly sold 250,000 copies. Barnes & Noble and Amazon aren’t disclosing sales.

Like Harry Potter, Twilight comes from a first-time author, and her success is about as unlikely as J.K. Rowling’s. Five years ago, Stephenie Meyer was a stay-at-home mom with three kids in Phoenix and no dreams of literary stardom. But she had a dream, literally, about an ordinary teenage girl and the handsome, passionate fellow who loved her. It was a perfectly promising romantic pairing, except the boy was a vampire. Next day, Meyer wrote her dream down. She wrote and wrote and publishers recognized a commercial opportunity. Meyer, 34, and her publisher, Little, Brown, have cleverly marketed the Twilight series online. Fan sites have proliferated.

To better grasp this phenomenon, I called Katherine Courtney, a 17-year-old pal of mine who bought Breaking Dawn in Rehoboth Beach, Del., last weekend. She took two days to finish 700+ pages. “It’s all about forbidden love,” she says. “Edward is so drawn to Bella’s blood. He wants to love her and kill her. It’s those opposing forces.” Katherine has read all four Twilight books and says that this latest one is “the most captivating.”

Let the boys have Harry Potter, Katherine says. She and her girlfriends adore Edward and Bella. “Harry Potter is all mythical,” she notes. “With Twilight, you get both the mythical and the human world.”