What happens after death?

Start where the book starts, with something you already know. Everything that is born also dies. The leaf, the sparrow, one day even the stars. The rishis just refused to drop the next question: when the body stops, does the person inside it stop too?

a teaching Their answer begins with an experiment you run every single night. In deep sleep you vanish. No thoughts, no dreams, no "me". Then every morning, someone wakes up who remembers being you. Something crossed that gap. The tradition calls it the atma, the Self, and makes its biggest claim about it:

"The Self is never born and never dies… it is not slain when the body is slain." — "As a person discards worn-out clothes and puts on new ones, so the Self discards worn-out bodies."

That long trip through many bodies is called samsara, and the picture for it is a wheel. Look closely at the picture though. The wheel has an exit. It is not a trap built to punish you. It is a school you can graduate from. And between bodies, the teaching says, a subtle carrier travels with the Self. It is called the sukshma sharira, and it holds your tendencies and your unfinished account, pulling the story into its next chapter.

The tradition's favorite take on this question is a story about a kid who would not be bought. The Katha Upanishad opens with a boy named Nachiketa standing in the house of Death himself, asking the one question adults dodge: what actually happens when a person dies? Death squirms. He offers the boy elephants, gold, kingdoms. Anything except the answer. The boy turns down every bribe. That is who this tradition picks as its hero: a child who would not be paid to stop asking.

outside the book And science? Honestly: nobody knows. No lab result settles what continues, if anything. Serious researchers on every side agree the question is open. Anyone who tells you science has closed it, in either direction, is selling you something.

The honest note The deep-sleep thing is an analogy. It points at the question. It does not prove the answer, and the book says so. Rebirth is stated here as a teaching: the tradition's considered answer, offered for you to examine exactly the way Nachiketa examined it.