Beneath the Patchwork Moon
In the first book Luna had a secret regarding her best friend Sierra. I was curious and wanted to know what it was. I had a hard time with this one. I thought Luna was too much a martyr/over-wrought and didn't understand why she kept silent (and guilty) for 10 years. Sierra's family blamed Luna for things that she couldn't control and were not at fault. It just got annoying.