Nothing that begins with champagne can ever be dreary. That is how A Day of Fire: A Novel of Pompeii began—with Stephanie Dray, Kate Quinn and me toasting the release of one of Kate’s marvelous novels. We three have a longstanding tradition of hanging out on release days, primarily to keep whichever of us has a book launching from relentlessly checking Amazon rankings or curling up in a fetal position (if you’ve never released a book, believe me it is as terrifying as it is gratifying). All sorts of things get discussed at these luncheons—including the types of plot points that seem perfectly normal to historical novelists, but send waiters scurrying away concerned. On that particular day, however, our history obsessed brains turned not to poison or regicide but to doing something creative together. Specifically to continuities—collections of short stories that each stand-alone but also interlink to form a larger novel—which were increasingly popular in historical romance, but hadn’t made the leap to straight historical fiction yet. Maybe it was all the bubbles, but we were determined to change that. Writing is generally a solo effort, and it can be lonely. So when you have a chance to work with…