In 1957, the vessel that T'Mir was serving on was investigating the first artificial satellite launched by Humans, then a pre-warp civilization, Sputnik I. Her vessel crash landed on Earth in the small town of Carbon Creek, Pennsylvania, in the United States of America. She took command when the captain of the vessel was killed in the crash. After running out of food, she and Mestral, one of her two remaining crewmates, walked to the town of Carbon Creek, stole Human clothes, and then entered a local tavern. Needing money, Mestral played a game of pool and won enough money to buy food.
T'Mir and her crewmates assimilated into the Human society while they waited for a rescue ship. T'Mir was employed as a cleaning lady in the local tavern. She had a pessimistic view of Humans, believing that they were on the brink of self-annihilation. She also cautioned her crewmates about getting too close to the Humans. When Mestral became involved with the tavern owner, Maggie, T'Mir warned him not to see her again. Her views changed as time went on.
She became interested in Maggie's son, Jack. Jack wished to go to college, but his mother could not afford it, even though she had set up a tip jar for the college fund. To help Jack out, T'Mir took something from the wrecked ship, traveled to Pittsburgh, and sold it to a businessman. It was an "invention" that was later called Velcro. She put the large sum of money she received in exchange for it in the college fund tip jar. T'Mir also helped her crewmates rescue miners trapped in a mine accident.
When a rescue ship finally arrived on Earth, T'Mir covered for Mestral, who wished to stay behind, by telling Captain Tellus that he had been killed in the crash, along with their captain, and that their bodies had been cremated. She and her crewmate, Stron, then returned to Vulcan.
While the crew's experience became well documented in the Vulcan archives, T'Mir kept some details, such as the true fate of Mestral, within her family. The purse she used on Earth was kept as a well-maintained family heirloom, which was among T'Pol's belongings on Enterprise in 2152. After T'Pol was stationed at the Vulcan Compound in Sausalito in 2149, she eventually took the opportunity to take a five-day leave to visit Carbon Creek and see it for herself. (ENT: "Carbon Creek")
T'Mir was played by actress Jolene Blalock.
Hair designer Michael Moore was thrilled with the character's physical appearance, later remarking, "What was really cool was that [T'Mir] looked so good with that hair and her outfit. Jolene has such a great body, and when you put that June Cleaver dress on that body – whoa! It was a fun change for us." (Star Trek: Communicator issue 152, p. 31)