This relatively new book is very similar in style to Robin McKinley's early works...until you get to the end.
In the world created within these pages, it is traditional for two peoples--the humans and the pegasi--to create a bond between carefully selected individuals in order for the races to better understand each other.
This is the story of a princess and her pegasus, and the secret that they uncover.
I didn't care for the ending at all--it was too abrupt, and didn't fully resolve things--but it was interesting until that point. However, the ending makes all the pages before it seem like wasted time, so I can't recommend this one wholeheartedly.