Outsiders
“Outsider” is a term inclusive of anyone living outside of the city’s immediate vicinity. People of the Annex don’t typically consider themselves Outsiders (though plenty of Boomtown’s residents would define an Outsider as anyone outside the outer wall).
So far, Outsiders appear to be dangerous. In Prologue, a Keeper was wounded by a small group of mostly-naked Outsiders adorned with animal bones and wielding spears. Afterward, the captain refers to the Outsider tribespeople as “savages” and “curs.”
Ricky makes two brief references to the Outsiders in Preamble: summing up the average slummer’s apathetic attitude toward the harshness of life on the frontier, he says, “the Outsiders can’t kill us all,” indicating the slummers also tend to regard those who would live in the Wilderness as fatally dangerous.
However, he includes among the residents of the Annex “Outsiders who can’t get in.” The Annex clearly sees its share of non-confrontational Outsiders, suggesting the perception of them as murderous savages may not be universal.