Also known as CT-27-5555, Fives trained with Domino Squad on Kamino before being shipped out to the Rishi Moon listening outpost. He survived the Separatist attack on the station there, and was transferred to the 501st Legion alongside his squadmate and fellow survivor, Echo. Fives and Echo were promoted to ARC trooper status after the defense of Kamino from Separatist invaders.
He and Echo were later assigned with the difficult mission of freeing Republic prisoners from the daunting Citadel prison installation on Lola Sayu. Though Fives survived that arduous assignment, Echo tragically fell in battle, leaving Fives as the sole survivor of the Domino Squad training squad.