Kerstin Gier writes young adult fantasy and romantic fiction, best known in English for the Ruby Red trilogy. Ruby Red follows Gwyneth Shepherd, a London teenager who unexpectedly discovers that she has inherited her family's time-travel gene and is drawn into a secret society that has been planning around another relative. Sapphire Blue and Emerald Green continue through historical missions, family secrets and her complicated relationship with fellow traveller Gideon de Villiers. Gier's books are light, fast and romance-led, with time travel used for mystery and social comedy rather than hard science fiction. They fit YA time-travel fantasy, romantic adventure and secret-society fiction. Ruby Red is the obvious entry point for Gier's time-travel trilogy, with family secrets and secret-society rules carrying as much weight as the romance. Read more Less