After meeting in the past in 2007’s The Magic Half, Miri and Molly land safely in the present—but not for long. In the sequel, Magic in the Mix (Bloomsbury, Sept.), Annie Barrows again whisks the girls back to an earlier era—this time the Civil War, where they must race against the clock to save two unusual soldiers and come to terms with Molly’s real past. The novel has an initial print run of 75,000 copies.

Writing a follow-up to her 2007 middle-grade novel was on Barrows’s mind for some time—more or less. “The idea of a sequel was percolating for a while, but at the same time I didn’t think that there was another book coming,” she muses. “I got many letters from readers asking about a sequel, and I kept thinking, ‘There’s isn’t one here.’ And then about two years ago, I suddenly had a visual image, which is a pretty rare way for me to start a story.”

That mental picture—of Miri and Molly realizing that the magic has returned to their lives—drew Barrows in. “This image wouldn’t leave my brain,” she said. “It was as though they were looking at me saying, ‘We’ve got to do something about this magic—it’s back.’ It was as though all three of us were in the same boat. And because I love these characters so much, I was on board.”

Barrows, who also writes the younger Ivy + Bean series for Chronicle, enjoys spending time in both worlds with their very different protagonists. “Ivy is my Dionysian character, who lights the world on fire,” she says. “Molly and Miri are a bit more mature, and most of the action in the magic books involves the girls puzzling out solutions—their issues are bigger, and more thoughtful. Ivy and Bean also think their way out of their troubles, but their dilemmas are funnier and simpler.”

It’s been a few years since California native Barrows has attended BEA, and booksellers will have several chances to welcome her back. Today, 10:30–11:30 a.m., she’ll autograph galleys of Magic in the Mix at a ticketed signing at Table 3 in the Autographing Area. And tomorrow, 11:30 a.m.–12:30 p.m., Barrows will join illustrator Sophie Blackall at the Chronicle booth (2827) to sign finished books and posters promoting Ivy + Bean Take the Case, due out in paperback in August.

Though she shares some light concerns about her visit to Javits (“How am I going to get a taxi cab? Where am I going to eat?”), Barrows enjoys BEA’s “sizzling” atmosphere. “It’s like a state fair—but with just book people,” she observes. “What could be more fun?”