Stanley pulls a limp Zero upright and then onto his shoulder, with Zero's legs dangling in front. He leaves the shovel and the jars behind and picks his way up the incline. Stanley feels as though God's Thumb is giving him strength and pulling him towards it. He begins to smell something foul in the air as the ground levels off. Stanley looks in front of him; the thumb no longer looks like a thumb and it's far too big to climb. He feels as though the smell in the air is the smell of despair. As Stanley heads towards the thumb, he slips, drops Zero, and lands facedown in a muddy gully.
Stanley's decision to carry Zero instead of abandoning him or staying put is a testament to Stanley's newfound appreciation for the boys' friendship, as he now sees leaving Zero as something wholly wrong. His conception of the smell as foul shows that this is a moment of doubt for Stanley; he hasn't yet learned to truly trust the natural world to guide him.
As Stanley laments his fate, he suddenly realizes that one needs water to make mud. He begins to dig in the wettest part of the gully and in the darkness is able to fill a small hole with dirty water. When Stanley has a reasonably sized hole, he scoops water and splashes it on Zero's face. Zero begins to stir, so Stanley pulls Zero closer and pours more into Zero's mouth. He discovers an onion as he digs for water and eats half without even peeling it. He gives the other half to Zero and tells him it's a hot fudge sundae.
Splitting the onion in particular shows that Stanley truly values Zero's life and their friendship; the presence of water and food suggests that Stanley's kindness, combined with nature's benevolence, will have the power to bring Zero back to life and wellness.