Pretty awesome, eh? You can click the link to Bookish up above to read a small spoiler-free blurb about the book. The only other thing I'll add is that the "choice" it refers to that the book focuses on is the big exciting that happened at the end of The Indigo Spell. That's all I'll say for now. Amazon has a slightly longer blurb, but it too is *mostly* spoiler-free since there are still many people who haven't read Indigo yet. (If you're worried, skip it for now).
The Fiery Heart comes out November 19 in English-speaking countries, and--believe it or not--it's even hotter than The Indigo Spell!