The Shadow of the Torturer by Gene Wolfe
Severian, an apprentice in the torturers' guild, barely survives a swim in the River Gyoll. On his way back to the Citadel Severian and several other apprentices sneak into a necropolis where Severian first encounters Vodalus, the legendary revolutionary. Vodalus, along with two others, including a woman named Thea, are robbing a grave. Vodalus and his companions are confronted by volunteer guards. Severian saves Vodalus's life, earning his trust and the reward of a single "gold" coin.