Part 4, Chapters 4, 5 and 6 Summary

The three friends have barely left Denver when Stan gets a bug bite from hanging his arm out the car window. Sal determines that this is a bad omen about the trip and the men determine to find a clinic to get some medical attention for Stan whose arm is swelling ominously. Dean is especially excited to be headed south as most of their trips have been east or west in direction. The men all take turns telling their life stories and leave no detail untold as the night and the road stretch before them.

Stan gets some medical treatment in San Antonio and Sal and Dean explore the bars while Stan recuperates a short while. Not long after, the men cross the border into Mexico where they exchange their dollars for pesos and delight in the authentic towns...