When writing a book, you go through a lot of rounds of edits, and therefore a lot of changes. Some are quite big, while others are tiny details that might go unnoticed by the reader but make a huge difference to the story.
I thought it would be interesting to share some of the changes in Lumi and the Wolf during the editing process, and some rather significant ones that happened after the proof copies had already been printed and sent out!
Spoiler warning: This article contains spoilers for Lumi and the Wolf, so if you haven't read the book yet, you might want to come back to it later!
How the story changed during editing
I can remember that when I first wrote the book, it started with Lumi arriving from the airport and soon meeting her cousin Oskár. If you've read the book, you know that it now starts with Lumi up in a tree, with Wolf staring up at her. Quite a change, huh?
Also, Oskar is no longer her cousin, but a local Sámi boy who decides to follow her and then join her and Wolf on their adventure, rather than being part of the trio from the get-go.
These were some of the bigger changes my editor and I made while working on the book together. By January 2026, we had reached the point where the proof copies were printed.
Proof copies are early reader copies that are sent out to the press, booksellers and book bloggers to get them excited about the book before publication. But here's the twist:
I hadn't yet been to Lapland in winter before the proofs were printed.
What I learned in Lapland
I'm from southern Finland myself, and when I wrote the book, I described Lapland as it is in the south, not realising how many mistakes I made. So when I travelled up to Lapland in February, I realised I'd got quite a few things wrong!
In the book I had described the trees as very tall, reaching for the sky. But when I arrived in Lapland, I realised that especially up on the fells, the trees are quite meagre. The climate is so harsh, and it's so cold that they don't grow very tall at all!
I'd also described the extreme darkness of the nights and said something like, "It's as dark as only an Arctic night can get." But then I travelled to Lapland and learned that it never gets completely dark! Because of the snow, every bit of light is reflected, even if it's only moonlight or starlight coming from behind the clouds, or the light from a town that's kilometres away. The snow will still reflect that light. In fact, my mum and I went snowshoeing at night in the national park without a torch, and we could still see where we were going!
This was something I definitely had to change, because Lumi and Wolf often hike at night, and now I knew that it was actually possible to see where they were going.
And then there were all the little details about what it actually feels like to be outside in temperatures of minus 26 degrees. I experienced a sauna and ice plunge. When I stood on the ice, my wet feet froze to the ground! Of course I had to add that description to the book. I wouldn't have known that if I hadn't tried it myself.
I also learned that your fingers start to ache the moment you take your mittens off in that kind of cold. And how your toes hurt, even if you're wearing multiple layers of socks.
These were all little things I could now describe much more accurately, because I had actually experienced them myself.
Structural changes
But other things changed too.
Writing a book takes a long time, and sometimes your brain will work on things in the background without you knowing. Then suddenly you realise how you could have fixed an issue, even though you're months too late. Thankfully, my publisher was understanding and let me make other changes after the proofs were printed.
For example, I had always intended for Lumi to talk about being autistic in the sauna. In Finland, the sauna is a place where people often confess their secrets because it's dark and you're naked, so it's harder to hide anything. For that reason, even important business meetings take place in the sauna.
But somehow, in the earlier version of the book, Lumi talked about her autism after the sauna. So by moving a few other bits around, I managed to move that scene back into the sauna, where it was always meant to be.
I also tightened up Lumi's and Oskar's conversations about the changing winters. In the proof version, they talked about winters three times, and about the disappearing winter vocabulary on top of that. Now I managed to compress those four conversations down to two, without losing what I wanted to say.
Another change was to the scene towards the end of the book, just before Lumi falls into the river. Originally, she was cheerful and going on a lovely, sunny winter walk. But I realised that this moment could be much more dramatic. So now, instead of an easy stroll, Lumi storms away in anger from Oskár, thinking her only friend has abandoned her. In her mind, both Oskár and Wolf abandon her. That makes what happens next much more dramatic, and it also gives the scene a lot more emotional weight.
I also added little details like the name of the city where Lumi is staying (Inari)
Bringing the themes back at the end
Another thing I worked on was bringing some of the themes from the beginning of the book back towards the end.
At the beginning of the story, Lumi thinks that being sensitive is a negative thing. But by the end of the book, I wanted her to realise that she's allowed to be herself. She's allowed to be sensitive.
I brought this theme back more clearly at the end, so that we can see how Lumi has changed during her adventure, and how she has started to accept herself as she is.
It's one of those changes that might seem quite small, but I think it makes a big difference to the story as a whole – and a big difference to neurodivergent readers, too.
So how different is the final book?
Proof copies let people in the book industry get an idea of what a book is about before it's published. So I'm sure that the people who read my proof copy got a good idea of what Lumi and the Wolf is about. The characters, the adventure and the heart of the story were all there. But quite a lot has changed since!
It was an exciting process for me, and I learned so much, not only about Lapland but also about writing and editing a book. It's interesting how even when you think a book is finished, there are still many, many things you can improve. In fact, there are about ten things I wish I had written, but only realised when the book was already published!
A summary of everything that changed after the proofs were printed
So, if you've read one of the early proof copies of Lumi and the Wolf, here are the things that are different in the final book:
The trees in Lapland: I changed descriptions of tall, strong trees to smaller, skinnier trees that grow in the harsh climate.
The darkness of the Arctic nights: I changed the descriptions of pitch-black nights to show how the snow reflects even the smallest amount of light, which makes it possible to see at night without a torch.
The birds: I removed birds that wouldn't actually be around during the coldest winter days.
The sauna and ice plunge: I added details from my own experience, including how my wet feet froze to the ice when I stood on it.
The extreme cold: I added descriptions of how your fingers ache when you take off your mittens and how your toes can hurt even through several layers of socks.
Lumi talking about her autism: I moved this conversation from after the sauna to inside the sauna, where I had always intended it to happen.
The conversations about changing winters: I tightened up Lumi's and Oskar's discussions about climate change and disappearing winter vocabulary, which hopefully reduced the feeling of repetition.
The scene before Lumi falls into the river: Instead of going on a cheerful winter walk, Lumi now storms away from Oskár, believing that both he and Wolf have abandoned her.
Lumi learns to accept herself: I brought the theme of sensitivity from the beginning of the book back into the ending.
So although the proof copies and the final book tell the same story, there are quite a few differences between them. And I think all these changes have made Lumi and the Wolf a stronger book.