AUTHORS are often tormented by their 'difficult second book' and Grappenhall writer Sally Green knows that feeling better than most.

The Grappenhall resident's fantasy story Half Bad was the bestselling UK young adult debut novel of 2014 and it impressed Twilight's producer Karen Rosenfelt so much that she snapped up the film rights.

So it goes without saying that expectations were high for the follow-up.

"I really learnt to respect anyone who writes a series of books," said Sally.

"I’ve always liked J.K. Rowling’s books but I respect her more now because I cannot tell you how hard it is to do a second book.

"You’ve got to remind the reader of what’s gone before but you can’t do it clumsily and then you’ve got to set things up for the book that comes after.

"Structurally it’s a complicated thing plus you’ve got to give the book its own story and make it as exciting as you can. It was harder than I thought but I loved doing it."

Sally's trilogy is about a boy called Nathan and his struggle for survival in a hidden society of witches. The sequel called Half Wild came out this week.

The books are hotly tipped to do for witches what Twilight did for vampires and what Harry Potter did for wizards.

"I think any resemblance to Harry Potter is fading fast," added the 53-year-old.

"It’s definitely getting darker. There have even been comparisons to the Bourne films because Nathan is zipping around Europe

"He’s in a race against time in the story to save Annalise who is captured at the end of Half Bad.

"Then also there is this big battle brewing between the white witches and the black witches.

"I could have made it purely into a love story but I wanted to make it bigger than that and bring in a tale of good versus evil.

"It became quite a complicated thing to do but it was still enjoyable. I still love writing."

Sally started the Half Bad series in 2010. She had not written fiction since her O-Levels but found time on her hands when her son Indy, aged 12, was at school.

She originally found inspiration after going to Fate, a storytelling festival in Shropshire, and five years on Half Bad is now available in 45 countries.

So did Sally worry about living up to the hype with Half Wild?

"I felt more of an obligation to my characters," she said.

"I want to write the best story I can and bring out the characters and their lives, almost as if they’re real to me.

"I wrote Half Bad when I didn’t have a publishing deal so I was writing it at all hours because I saw it as a hobby.

"Whereas with Half Wild I had a deadline and quite a bit of pressure. Because of the success of the first book I had to deliver a second book that was just as good.

"I did feel under quite a lot of pressure so I approached it much more like an ordinary job starting at 9am and working through.

"The whole thing has just been amazing. I still have to pinch myself and remind myself how lucky I am to have Penguin as a publisher. It’s thrilling

"I still get excited when I see my novel on bookshelves and what I think is really nice is when you hear from readers.

"They might tweet me or send me a comment on Goodreads and I do really appreciate it when someone says they’ve enjoyed my book. Something as simple as that is still really lovely to hear."

The idea for Half Bad cast its spell on Sally when she allowed her mind to wonder while going for walks in Lumb Brook wood.

Sally, who has lived in Warrington with her husband Allan for more than 20 years, added: "If I need to think quietly about the book then I will go for a walk there.

"I also go up to Grappenhall Heys Walled Garden. It’s really peaceful."

Among Sally's biggest fans is her son Indy.

She added: "He’s really proud. It’s lovely. It’s really sweet. A lot of his friends at Bridgewater High are reading the series.

"It’s great. I love the thought that kids I know are enjoying my book."

DAVID MORGAN