"I love Ōtaki and it was glorious to be there for weeks on end, just my husband and I.
"Without the distractions of normal life, I was able to get on and write.
"I sat at my desk for hours every day and just wrote."
Influenced by events happening around the world, Eirlys was writing at a time it looked as though Donald Trump might win a second election which terrified her, while also being inspired by the likes of Greta Thunberg who was fighting for the action on climate change.
"I'd been playing around with ideas for the sequel to The Mapmakers' Race for some time.
"The Mapmakers' Race ends with the children reunited with their mother and planning an expedition to find their father who's disappeared.
"I couldn't leave the sequel too long or the children who were waiting to find out what had happened to the Santanders' father would be all grown up.
"As I was writing it looked possible that Trump would be elected for a second term and that thought terrified me.
"At the same time inspirational young people like Greta Thunberg were fighting for action on climate change and I realised that the father's disappearance was tied up with the actions of a despot and the future of a community.
"I'm not a planner, so I wrote whole chapters that I ended up throwing away, but it was good to see the file growing, and there was plenty going on in the world to drive the story forward."
In the part detective story, part adventure, the whole community sticks together and acts collectively to force change.
"As a child I was obsessed with the idea of flying and of seeing the world from above.
"I also liked adventure stories about children who were competent and knew how to do things I couldn't do.
"All these elements plaited together to make The Mapmakers' Race and then The Uprising."
The Uprising contains contemporary themes about the environment and rebellion, which Eirlys hopes will resonate with young readers.
The book has been illustrated by Kirsten Slade, with maps showing the town of Cruxcia and the Afa Valley where the story is set, just as Eirlys imagined it.
Launching at Books and Co Eirlys said, "It's wonderful that we have an independent book shop in Ōtaki and I want to support Jacqui Simpson as much as I can."
The booklaunch is on Saturday, from 3-5pm at Books and Co in Ōtaki.