Gemma Chan (born 29 November 1982) is a British film, television and theatre actress and former fashion model. She portrays Charlotte in season four of the Showtime and ITV2 series Secret Diary of a Call Girl; Ruth in Channel 4's Fresh Meat; Mia Bennett in the BBC's Doctor Who "The Waters of Mars" and Soo Lin in Sherlock, She also appeared in Exam and Paramount Pictures' action-thriller Jack Ryan: Shadow Recruit. She stars in Humans, an AMC/Channel 4 eight-part science-fiction drama, which premiered in June 2015.