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 assigned with the difficult mission of freeing Republic prisoners from the daunting Citadel prison installation on Lola Sayu. He and Echo were later part of a mission to free Republic prisoners from the Separatist prison called the Citadel. Echo fell in battle, leaving Fives as Domino Squad's sole survivor. Fives accompanied the clone trooper Tup to Kamino for medical testing, where he discovered a terrifying secret about the clones' origins and ultimate purpose