Fall Woo was a sworn brother of the Black Company mentioned during the events of "Bone Eaters", one of the short stories of the On The Long Run arc.
Fall Woo, Whittle, Rusty, and Robin led a haggard-looking scout group at the head of the Company and the long train of refugees from the Lady's Empire that followed them in the western wilderness. With them was the wizard Goblin, concealed in a goat cart, and behind them was a hidden guard posse including Croaker. Fall Woo and his group encountered a band of 7 amateur brigands and captured 6 of them. One of them was Chasing Midnight, a young woman who would play an important role in the weeks which followed, and another was her twin brother Chasing Moonlight. (Later events would reveal the names of the others: Chick, Fade, Haru, and Yuko.)
Fall Woo is not mentioned again in the available Annals. But like all other brothers mentioned prior to the Battle of the Barrowland who were not among the only 10 Company survivors of that battle, he must be either deceased, missing, discharged, or possibly even a deserter by the end of The White Rose.