The boys buy a new mule in Hornsilver

Filthy, hollow-eyed, and newly alone, Elliot and Ethan go to the livery and buy a rough mule with Sam’s money. The animal is stubborn, unimpressive, and absolutely necessary.

This is a strong “forced into adulthood” image. They are not pretending to be men now. The world is making them act like men before they are ready.