Kerstin Gier (born 1966) is a German author of novels for adults and young adults. Her popular young adult novel *Rubinrot* (*Ruby Red*) and its two sequels - a series about time travel - as well as her Silber trilogy were translated into English by Anthea Bell. Kerstin Gier has also published books under the pseudonyms Jule Brand or Sophie Bérard. **Source**: [Kerstin Gier](https://en.wikipedia.org/wiki/Kerstin_Gier) on Wikipedia