Redemption is an important theme in the story. As the title implies, the characters are outcasts, expelled from so-called respectable society by its self-appointed moral guardians. Yet in the midst of extreme adversity they show themselves to be more moral than those who banished them. Oakhurst, the professional poker player, shows kindness in trading his horse for the Duchess's mule; he also redeems himself by giving Tom back the money that he cheated him out of years before and telling him not to gamble anymore.
As for the Duchess, a notorious prostitute, she achieves redemption in a number of ways. The Duchess, along with another prostitute, Mother Shipton, spares Tom and Piney considerable fear and anxiety by not telling them about Uncle Billy's making off with the mules and provisions, which has left the party of outcasts in serious danger. Even more astonishing is the behavior of Mother Shipton, who sacrifices her life by giving her few remaining rations to young Piney.