The car's headlights don’t work, so Sal, Dean, and Stan drive in the dark.
They get to the Tropic of Cancer.
They’re still high and they’re in the jungle, which they think is a pretty sweet combination.
They try to sleep in the car, but it’s ridiculously hot. There are also millions of mosquitoes.
Figuring that he’s already been bit thousands of times, and that malaria is probably not the worst thing in the world, Sal sleeps on the roof of the car, clotting up dead bugs all over his back and becoming bloody and part of the jungle.
A policeman finds them sleeping and says, carry on, young men.
Sal has another vision, a wild, white horse riding past Dean, followed by barking dogs. He wonders about this dream until Dean reveals the next morning that he, too, dreamed about a white horse.
Some HUGE bugs follow them out of the jungle. Sal’s the only one that seems to care.
They dig the smell of blood, dead bugs, sweat, and jungle on their bodies.
On some high terrain they meet a three-year-old Indian girl that Dean talks to. He observes her carefully and narrates her life to Sal and Stan.
They meet more Indian girls, but Sal says they don’t have any sexual urges toward the girls (which is most definitely a first). He compares them to the Virgin Mary.
Dean gives a little girl a watch in exchange for a small rock-crystal. The little girls run after them when they leave.
Sal wonders at how they are so at peace, unaware of wars and bombs and other generally unpleasant things in the world.
They get to Mexico City and wear their bug and bloodstained t-shirts into town.
There’s noise and traffic and motion, the last of which gets Dean incredibly pumped.
It’s all pretty groovy until Sal gets dysentery and becomes feverish. He has dreams and other fever-related hallucinations, and then Dean peaces out to go back to Inez in New York, leaving Sal in Mexico in a haze.