Kerstin Gier

A very well recieved series by Kerstin Gier are the books, featuring tropes. The most popular books are Saphirblau, Ruby Red, Emerald Green, Emerald Green (The Ruby Red Trilogy 3), Saphirblau (The Ruby Red Trilogy 2), Ruby Red (The Ruby Red Trilogy 1), Ruby Red (The Ruby Red Trilogy #1), Saphirblau (The Ruby Red Trilogy #2), Dream On, Just Dreaming, Sapphire Blue, A Castle in the Clouds, which was published in 2022.