The story "A Sound of Thunder", by Ray Bradbury, begins in 2055 A. D. When Eckels, Protagonist, wants to hunt a Tyrannosaurus Rex. The costly venture begins and they go back into time, the Jurassic Period, on an approved hunt. Through the travel, the hunters wear oxygen helmets when under way to the past. Travis, the guide, says that no one knows for sure if time can be altered, but it isn't worth the risk Furthermore he explains the domino effect that interacting with things could have upon the world. Further building the plot they step from the time machine Eckels is told not to step from the path, as they come upon the Tyrannosaurus Rex, marked with red paint you can hear thunder, Mr. Eckels gets frightened and strays off the path stepping