A Sound of Thunder by Ray Bradbury
Quick answer: A Sound of Thunder by Ray Bradbury: summary with the ending, Eckels and Time Safari, the Path, the Tyrannosaurus, the butterfly, and the changed election.
A man named Eckels pays ten thousand dollars to hunt a Tyrannosaurus rex sixty million years in the past, and the safari company's first rule is that he must never step off the Path. Ray Bradbury published A Sound of Thunder in Collier's in June 1952 and collected it in The Golden Apples of the Sun (1953).
It gave American classrooms the butterfly effect as a plot, and it ends in one line of sound.
The story in brief, ending included
In 2055 Eckels arrives at Time Safari, Inc. the morning after the moderate Keith has beaten the authoritarian Deutscher for president; the clerk is relieved. The guide, Travis, explains the rules: the hunters walk on an anti-gravity Path that floats above the prehistoric ground, they shoot only animals the company has scouted and marked with red paint because they were about to die anyway, and they retrieve every bullet. Crush one mouse, Travis says, and you may erase the descendants of a billion, and eventually a president.
The Tyrannosaurus arrives, and Eckels, who has bragged about his kills, goes to pieces at the sight of it. He stumbles off the Path into the mud while Travis and his assistant Lesperance kill the animal, which is then crushed by the falling tree the scouting predicted. Travis, furious, makes him dig the bullets out of the carcass with his hands. Back in 2055 the office smells wrong, the sign on the wall is spelled in a coarsened language, and the clerk says Deutscher won. On the mud of Eckels's boot is a dead butterfly. Eckels begs to go back; Travis raises his rifle, and the story ends with a sound of thunder.
The characters
Three hunters and one insect.
Themes: small causes and the arrogance of the hunter
The classroom readings are cause and effect across time, responsibility that comes with power over nature, and cowardice against discipline. The changed election supplies the political meaning; a democracy is only as safe as the chain of tiny events that produced it.
The sharper point is the story's economy of proof. Bradbury shows the altered world through spelling, smell and one sentence from a clerk, and never explains the mechanism. The reader is trusted to assemble the disaster from the butterfly and the ballot.
The craft: a rule stated, a rule broken, a bill paid
The opening front-loads the rules so the story can spend its middle on spectacle; the Tyrannosaurus is described at length precisely because Eckels's collapse must feel earned. The turn is his step off the Path, a single physical action. The ending pays off Travis's lecture about the mouse with the butterfly, and closes on the rifle rather than on explanation.
The technique to steal is the sensory proof of change. When a world shifts, show it in the small evidence a character would actually notice, a misspelt sign, a strange smell, before the large fact arrives.
For class and essays
Model answers, vocabulary, one misreading.
What writers can take from this
- For exams, quote Travis's mouse argument in your own words as the story's thesis.
- Cite the spelling of the sign and the changed election as the two proofs of the altered world.
- Note that the butterfly is described as green and gold; small detail makes the loss concrete.
- Writers: state a rule early and let one character break it for a believable reason.
- Show a changed world through small sensory evidence before the large fact.
Try it yourself
Write a story built on one rule stated clearly in the first page and broken, out of fear rather than malice, in the middle. Show the consequence first through three small sensory details the protagonist notices on returning, and only then through one line of dialogue that names the disaster. End before the punishment is shown.
Questions
What is the theme of A Sound of Thunder?
That small actions carry vast consequences, and that power over nature demands discipline. Eckels's panicked step off the Path kills a butterfly and changes an election sixty million years later.
What happens at the end of A Sound of Thunder?
Back in 2055, Eckels finds the sign misspelt and the authoritarian Deutscher elected, and sees a dead butterfly on his boot. Travis raises his rifle and the story ends with a sound of thunder, implying he shoots Eckels.
What does the butterfly symbolise in A Sound of Thunder?
The fragility of history: one small death alters everything downstream. The story popularised what is now called the butterfly effect.
By the Writory editorial team, reviewed by working writers. Updated September 2026.
Enter a Writory story contest
Enter the Writory Short Story Contest and have your own story read and scored out of 100. Entries close 25 November. That first entry makes you a Writorian.