It’s good luck for July and his party to have run into Gus, too, lest they have otherwise stumbled right into Blue Duck’s camp. The situation they’ve encountered reinforces just how unprepared they are for the wild and unpredictable circumstances of life on the frontiers of the country. Gus, ever the keen observer of human character, sees that July needs him more than he needs the sheriff. But he can’t afford to be too picky about help given his circumstances. The sound as they cross the river recalls the moment where the stampede wakes Newt and strongly hints that Blue Duck has already eluded them.