A member of the Coruscant Guard, Clone Commander Stone (clone designation CC-5869) spent long stretches of the Clone Wars far from the front on the Republic's capital world. He was able to make use of his combat skills when pirates attacked his shuttle during a diplomatic mission to Florrum -- though nothing in Stone's training prepared him for taking orders from a Gungan politician.
As a member of the Coruscant Guard, Stone's primary responsibility is to protect the Republic capital of Coruscant and its institutions, leaders, and people. It's a prestigious post, but a frustrating one for a clone trained for war.
The Republic sent Stone to Florrum to deliver a fortune in spice to the pirate Hondo Ohnaka in return for Hondo's captive, the Sith Lord Count Dooku. But Hondo's pirates wanted the spice for themselves, and betrayed their boss.