Shelby, also a surveyor and possibly unstable, accompanies the party westward and questions Dixon about the line. Dixon and Zhang then converse and arrive at the subject of dragons, whence Dixon relates the long tale of the Lambton Worm, conquered by a returning crusader who, following the battle, broke the oath he swore with God in order to achieve victory—an act that left his family cursed for nine generations. The party discuss and interpret the tale, and Shelby suggests, perhaps menacingly, that the surveyors accompany him to a "serpent mound" whose design can only be appreciated from far above, alluding to Dixon's past with Emerson and the ley-lines.