Trillian (character) family name McMillan
Tricia Marie McMillan, also known as Trillian Astra, is a fictional character from Douglas Adams' series The Hitchhiker's Guide to the Galaxy.  She is most commonly referred to simply as "Trillian", a modification of her birth name, which she adopted because it sounded more "space-like". According to the movie version, her middle name is Marie.  Physically, she is described as "a slim, darkish humanoid, with long waves of black hair, a full mouth, an odd little knob of a nose and ridiculously brown eyes," looking "vaguely Arabic."Biography
Tricia McMillan is a mathematician and astrophysicist whom Arthur Dent attempted to talk to at a party in Islington. She and Arthur next meet six months later on the spaceship Heart of Gold, shortly after the Earth has been destroyed to make way for a hyperspace bypass. The trilogy later reveals that Trillian eventually left the party with Zaphod Beeblebrox, who, according to the Quintessential Phase, is directly responsible for her nickname.
In the radio series, she is carried off and forcibly married to the President of the Algolian Chapter of the Galactic Rotary Club and consequently does not appear in the second radio series at all.  The later radio series (the Tertiary Phase and beyond) reveal this (probably) occurred only in the artificial universe within the Guide offices.  In the books, which the third, fourth and fifth series follow, she saves the universe from the Krikketeers and later becomes a Sub-Etha Radio reporter under the name Trillian Astra.
Some drafts of the movie's screenplay, and Robbie Stamp's "making of" book covering the movie, state that Trillian was to be revealed as half-human, an acknowledged divergence from Douglas Adams' original storyline. This would have been done in order to underline the loneliness of Arthur Dent, the only 100% Homo sapiens remaining in the universe, after Earth's demolition. This idea was scrapped after the "making of" book was written, and the scene revealing Trillian's heritage (by the mice, to Arthur, on the Earth Mark II) was re-written. An interview with actress Zooey Deschanel, included on the DVD version, has her mention that Trillian is half-human, suggesting the interview was recorded prior to the change of plan.
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