Some time in the past, Tara worked on a case with John Winchester during which they had a romantic weekend together. During the course of the case, Tara and John captured a demon who worked for Abaddon. They interrogated the demon who told them of the Knights of Hell and the First Blade, the weapon the Archangels supposedly used to kill them. Tara took notes on the demon's information and once they were done with it, the hunters exorcised the demon. John promised to call her but never did. However, while John never believed in the First Blade, Tara did, seeing such a powerful weapon as a powerful tool for any hunter. Tara then spent years hunting down the Blade, ruining her life and knee, but was only ever able to find a tracking spell that she could never complete as she lacked the last ingredient, essence of Kraken.
After learning of her existence, Dean Winchester and Crowley tracked her down. Though Tara was wary of working with them as Crowley was a demon, Dean convinced her of the threat Abaddon posed and she told them all she knew about the Blade. Crowley was able to get the last ingredient for the spell and it pointed to a location in Missouri. While Dean offered Tara to join them in continuing the hunt for the Blade, Tara refused as she wouldn't work with Crowley, warning Dean about working with him as she did not trust Crowley. Later, she was attacked by a demon looking for information on Crowley's actions. She tried to fight back but was overpowered. The demon tortured her until she told him what she knew and then he killed her. Her death was avenged by Dean who later killed the demon.
Dean later accused Crowley of inadvertently causing Tara's death by not warning them about the demons following them, to which Crowley reacted indifferently.
- According to Tara, her knee would react to the presence of nearby demons.