Walter is an elderly farmer from the village of Simb, a day or two south of Tyr, A month or two ago, his village was overrun by a group of Red Chord members led by Darok. Many of the villagers were killed, and many (including Walter) were captured and sent to join the growing slave pens outside Altaruk.
As the end of the Season of the Dragon drew near, Walter and several other slaves saw their chance and staged a breakout. Pursued by Night Runner elves and jhakar, the slaves were rescued from capture by the intervention of the PCs. Walter alone circled back to help the PCs fight the Night Runners. After the battle was over, Walter provided the PCs with some information about the camps outside Altaruk, accepted a survival day, and began a likely-doomed journey back towards Simb.