Inevitably, the books you read in childhood hold a special place in your memory. For children's author Pamela Butchart, it was Enid Blyton books and especially The Secret Seven mysteries that she fell in love with at a young age.

As a huge childhood fan, Butchart certainly never thought she'd find herself in the position of being approached by the publisher holding the rights to Blyton's books with an eye to continuing the series.'I thought she [Pamela's agent] was winding me up. I asked her to go back and check they had the right Pamela Butchart.'

As the news sunk in, Butchart started to re-read The Secret Seven books. 'It was so interesting,' Butchart says, 'as I realised why I loved them as a child. They are so accessible, and they are all about the children. I honestly hadn't realised how inspired I'd been by them.' She wasn't allowed to tell anyone for six months, and then after the excitement, Butchart says 'the fear hit. Secret Seven was the first series I had read by myself. I remember being excited I had finished a full book on my own and I could go to the library and get the next one.'

How did she conquer the fear? By realising she wasn't re-writing anything. 'I'm just bringing these characters back to life for a special two books. Everyone at Hachette were keen for me to come up with my own ideas. I wanted to keep characters and the setting as it was. I didn't want to introduce any new technologies such as mobile phones. It was all familiar surroundings. Just two brand new stories.'

There were two things Pamela was keen to change though, 'one was to make the language more familiar for 2019. I also wanted to inject a bit more girl power.' As she dived back in the world of The Secret Seven, it became obvious that the two main girls, Barbara and Pam, were not part of our modern vision of equality. 'They were always in the background giggling and being silly and when I started writing the first book I thought, "this is going to be a challenge". I wanted to bring them out of the background but also stay true to the dynamics of the friendship group. So, they became wild. And before I knew it, they took on a life of their own.'

Secret clubs are a strong theme in all of Butchart's books and as a child she was often the creator of many of them. 'I was a bossy wee thing. I remember that sense of belonging and excitement. No matter what, we were bound together by this group. It's great for imagination and for friendships.'

Her appearance at Edinburgh International Book festival will focus on The Mystery of the Theatre Ghost story and will welcome old fans as well as new. 'It'll be lots of fun, lots of volunteering from adults forced to get up on stage. We'll be making a new Secret Seven story too as it's not just me who can make up new stories like this.'

Pamela Butchart: On Stage with the Secret Seven, Spark Theatre, George Street, 24 Aug, 3.45pm, £5.