“I love the sea, I love boats, I love the water.” These are exactly the passionate words that fans of the Emily Windsnap books – featuring a 12-year-old girl who discovers she’s half mermaid – might expect from Emily’s creator, British author Liz Kessler. Emily’s maiden voyage, The Tail of Emily Windsnap (Candlewick, 2004), first landed on U.S. shores 10 years ago, and was also Kessler’s debut novel. In the past decade, the series – five books so far – has reeled in more than 2.6 million copies in total sales of all print and e-book editions.

It was in the late 1990s that Kessler saw the early glint of what would become Emily’s story, while looking out at the water she so loves. “It started off as a poem,” she recalled. “I’d left a job and was working toward a novel-writing master’s degree. I lived on a boat at the time and I got this idea for a poem about a girl who lived on a boat with her mom, and the girl had a secret – she would sneak off at night to go play with the mermaids.” A friend of Kessler’s admired the poem and showed it to her editor. “The editor thought I should write it as a book,” Kessler said. “When I wrote out chapter one, I thought, where do I go from here? I thought maybe it would be a 48-page picture book.”

Even though she was in uncharted waters, Kessler noted, her ensuing course to publication was very smooth. She chipped away at turning her tale into a novel while finishing her master of arts degree in creative writing and working various jobs, including one at an editorial services company. It was there that a colleague mentioned Kessler’s manuscript to literary agent Catherine Clark, who was just beginning to take on children’s books. “She asked to see it,” said Kessler. “I sent it on Friday and on Monday morning she called to say she wanted to work with me.” Clark negotiated a contract with Judith Elliot at Orion and The Tail of Emily Windsnap moved full steam ahead.

Karen Lotz, president and publisher of Candlewick, acquired rights to publish the books in the United States. Kessler hardly envisioned a series of titles starring Emily, however. “My initial deal was for two books, and I already had an idea for the second one,” she said. “But that’s as far as my thinking went.”

In fact, after completing the first two books about Emily, Kessler wrote A Year Without Autumn, a standalone title that incorporates the idea of time travel. Her editors advised that the timing was probably not right to publish that book, though, and wanted to hold it back (Candlewick eventually published Autumn in 2011). Wondering what to do next, Kessler went straight to her readers for a bit of advice. During a school visit she explained her dilemma to the students, asking them which project she should pursue. “The girls helped me decide,” Kessler said. “They voted that I should do a third Emily book.” In 2007, Candlewick published that third book, Emily Windsnap and the Castle in the Mist.

The series has continued to expand organically. “I thought I’d come to the end with book three,” said Kessler, “but at the end of that book everyone was asking me, ‘Will Aaron be Emily’s boyfriend?’ And then when I was writing book four, I discovered some amazing things about the other characters to be explored further.” Book five, Emily Windsnap and the Land of the Midnight Sun, came out in February 2013. And the author has just begun work on a sixth Emily Windsnap book, tentatively scheduled for fall 2015. When asked if she envisions the end of Emily’s story, Kessler noted, “If I come to a point I’ve run out of ideas, I’ll stop. I don’t want to milk it.”

Looking Back, Moving Ahead

Among the retail fans of Emily Windsnap is Barnes & Noble. “The series has been a great success for us,” said B&N buyer Brian Monahan. He noted that the Emily titles have been spotlighted in various fantasy and adventure, summer reading, and Great Reads for Young Readers promotions over the years. And, he added, “They have consistently been among our bestselling titles in the young reader category [fiction for 8-12-year-olds].”

Not surprisingly, the Emily Windsnap audience is predominantly tween girls. As Kate Fletcher, Kessler’s editor at Candlewick since the fourth Emily title, put it, “I think the Emily books appeal to middle-grade girls because Emily and her friends are very relatable, yet there’s plenty of magic and whimsy to keep them fun.”

Hollywood-based producer Reid Shane (recently of the TV series Fringe and Almost Human) was taken by the books as well, and optioned the Emily Windsnap series for film back in 2010. “He’s been working with me for 18 months or so,” said Kessler. “Alison Schapker [another Fringe veteran] wrote a treatment that I liked, and her screenplay was just finished a few weeks ago. I absolutely love it.” That screenplay is currently being sent out in hope of attracting studio interest. “It’s been so positive,” Kessler said of the process thus far. “They’ve been very keen to make sure I’m happy along the way, and I know that’s not always the case.”

Though there are no particular party plans for Emily Windsnap’s 10th anniversary, Kessler and her publishers appreciate that there is plenty to celebrate. The first Emily bind-up, of books one and two (The Tail of Emily Windsnap and Emily Windsnap and the Monster from the Deep), will be released this fall. And Kessler’s other middle-grade series, Philippa Fisher, about a girl with a fairy godsister, is being relaunched early next year with new cover designs; in the meantime, the first book, Philippa Fisher’s Fairy Godsister, will be part of a Barnes & Noble summer reading promotion. The author has kept busy with other non-Emily writing as well. A Year Without Autumn was followed by North of Nowhere (Candlewick, 2013), another standalone time-travel tale, and an early-reader series, Poppy the Pirate Dog, was inspired by her real-life Dalmatian, also named Poppy.

Looking back on her decade as an author, Kessler shared some thoughts about her readers. “It strikes me that the books today are written for a whole new generation of girls,” she said. “I feel like I’ve just got going! That blows my mind. The world has changed a lot in 10 years – technology especially – but I hope most of my audience is still just below the age where that really matters.”

When asked what has surprised her most about her writing success, Kessler replied, “All of it, totally. I find it really strange that I can sit here at home at my computer wearing pajamas or scruffy jeans or something, and I’m getting emails from parents telling me about the impact of my book. When someone tells me that their daughter has never wanted to read before but she loved my book, it knocks me sideways, every time it happens. The fact that I can reach right into someone’s life and have an impact is amazing.”

An anecdote about a recent experience in her hometown of St. Ives exemplifies the kind of serendipitous joys that authorship can bring. “I was walking home with the dog when a sudden hailstorm came on,” Kessler said. “I ran into the doorway of the local bookshop and asked if I could shelter there for a bit. A woman came in with her daughter and son, and while the children played with Poppy the mother and I got to talking and I told her I was an author. She bought two of my books for the children and I signed them. Then another woman came into the shop specifically to get one of my books. It was a little moment of feeling like a local star. It’s lovely when that happens.”