There seems to be a serious continuity problem here. In Chapter 4, Rinker is dismayed to discover that his "Trail Pup" won't work for the journey. As a backup plan, he's sure to select a mule that he can actually ride. Mere pages later, they're putting a sign on the back of the Trail Pup, and then in subsequent chapters, it's clear they've brought it along on the journey. What? Did I miss something?