I only have one word for this book: MAGICAL 
 Oh, this opening scene where Cora wakes up in a strange place!!!....Delicate furniture and mirrors all around, a blond girl was singing "tra la la, la la" dancing around, the birds were singing "chirp chirpity chirp" ie "you are not dreaming" in plain english, three magnificent horses with three magnificent riders at the courtyard wearing fluffy feathers. I was totally hooked to the story from the start. I am a sucker for fairytales. Totally addicted. 
 Out of the three horsemen, Tor (Cora's future sweetheart) will be the dark one, he will always look pissed and this seems it will be the only emotion he has until the middle of the book. Although he will save Cora from monsters in the beginning, he will be cruel to her. He will drop her in a dusty cave and he will make her eat Thumper, a sweet bunny. Cora tries to explain to him from the beginning that she is from a different world and now she is scared and confused and knows nothing about her evil twin. But he is a jerk. And he will be a jerk for most of the book. 
 Well, I read a saying somewhere that "marriage is loving someone so much that you forgive them occasionally for being a freaking asshole". Cora will forgive Tor occasionally A LOT. Anyway, he is a prince who hss never denied anything and who cannot not trust his wife enough based on his previous experiences and on her past behaviour. It is normal for him to behave as an asshole - not that I am making excuses for him. 
 My favourite scene is when Tor is transported to out dimension and he meets Cora's parents. And when her father asks Tor "Are you drugging her fruit juice? Are you in some kind of cult?", I could not stop laughing. It seems that all parents are the same in all countries of the world and whether they are hippies or not. Her parents are so cute. 
 Another thing I would like to mention is that I love that all girls in the series are slightly older (Cora is 32). They are girls next door, not very rich, not well educated, but with a strong spirit and an innocent soul and they live a simple life before they become Queens and Princesses. Loved them!