The final book in the trilogy, picking up from where we left off at the end of book two, when Amelia ended up coming to live with Father Christmas. She’s now attending school with the elf children, and struggling to get to grips with their subjects (elf maths is VERY different, eg: 2+2=snow, or a feather duvet), and she just doesn’t feel like she fits in.
There follows an accident with a sleigh, an elf that hates humans and spreads fake news about them in a very Trumpian fashion (this book was published in 2017, and you can tell!), and a warren full of rabbits, led by the Easter bunny – standard kids Christmas stuff, right?!
One problem that made me chuckle is that money in Elfhelm is chocolate coins, and when Father Christmas goes to withdraw money to cover the damages from the sleigh accident, it turns out that he has very few savings left as he ate it all… oops! And there is a point where our heroes are at great risk of being drowned in chocolate, what a pickle!
I’ll leave you with a line I thought was just beautiful:
“Books and trees are the same thing. My aunt used to tell me that books are just trees that are having a dream.”
ineke.co.uk 
Anything to add...?