TK-529, referred to as "Grimes" by his fellow soldiers, served as a stormtrooper on Hockaleg as part of a garrison during the era of the Galactic Civil War. His duties involved supervising the workforce involved in the construction of the super weapon known as Tarkin above the planet. While serving, news of Darth Vader's arrival at the space station reached him, which he passed on to his colleague TK-813, who then informed the experienced CT-4981. When the station was destroyed by the rebel alliance through sabotage, the planet's workers revolted against the occupying Imperial forces, resulting in the deaths of all garrison soldiers, including TK-529.