The writing team of Marisa Carroll came about when one half, Carol Wagner, parted company with her first writing partner, an old high school friend, after publishing two books. Carol saw the writing on the wall -- the line they were writing for was on life support -- her friend didn't. It looked like it was back to being 2nd shift charge nurse at Oak Grove nursing home. Enter the second half of the duo: her sister, Marian Franz, who had been typing heroically on an almost worn-out Selectric, and editing industriously with two toddlers hanging onto her pant leg since the beginning of Carol's now sputtering career. Try writing for Harlequin, Marian said. I don't want to do it alone, Carol replied. I loved talking story ideas over with someone else. I hate all that grammar and stuff. We'll do it together, Marian said. I already type your manuscripts anyway. So they gave it a try. The combination has lasted for 28 books, 26 of them for Harlequin's various lines. Ideas come from one or both. Carol does most of the writing. Marian does the research, all of the editing and proofreading, and ruthless weeding out of run-on sentences. The partnership isn't always smooth sailing, but like most long-term relationships, even those among non-siblings, the sisters have learned to put petty differences aside for the greater good of the book. Marian sometimes longs to sit down in front of the computer in her pajamas instead of donning panty hose for her job at Bowling Green State University, and Carol envies her younger sister her excellent health benefits and pension plan. But they've established a goal of 50 published books, a kind of Golden Anniversary for the partnership. And they intend to stick to it, no matter how many arguments it takes.