Originally viewed by her crew mates with resentment and suspicion, T'Pol has been forced to earn the trust of fellow officers. The character of T'Pol has developed from that of a "broken record" spouting the dogma of the Vulcan Science Council to that of a questioning scientific mind. Though she does not openly defy or reject the rulings of the Vulcan Science Council, her experiences on Enterprise have proven to her that they can be wrong.
T'Pol serves as a icon of Vulcan integrity. Her willingness to question the stale, self-serving decisions of her superiors, and her respect for Captain Archer position her at the fulcrum of Human/Vulcan relations (as well as the cat-suit which doubtlessly distracts the male bridge crew members).
In season three, T'Pol resigns her commission to the Vulcan High Command to accompany the crew of Enterprise into the Delphic Expanse to find the Xindi, a mysterious race accused of killing millions of humans on Earth in 2153.