Kerstin Gier (born 8 October 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. == Bibliography == === Young adult books === ==== Gem Trilogy ==== Rubinrot, 2009 (Published in the United States as Ruby Red, Henry Holt and Co., 2011) Saphirblau, 2010 (Published in the United States as Sapphire Blue, Henry…