A dead mouse here makes an insect imbalance there, a population disproportion later, a bad harvest further on, a depression, mass starvation, and finally, a change in social temperament in far-flung countries.

As Travis explains the reason why they must stay on the path, Eckels prods for additional explanation. Travis’s response, which includes these lines, emphasizes an understanding of the intricate web of cause and effect that appears throughout the story. Travis’s words show how seemingly trivial causes, such as one wandering step from a proscribed path, can result in greater, perhaps disastrous effects. By tracing events that might follow the death of a single mouse, Travis, in a burst of foreshadowing, offers clear reasoning as to how one accidental death might trigger a chain of events that have a tremendous impact on human society. Each action, no matter how small it may seem, can have far-reaching consequences.

Travis’s explanation, by all accounts, convinces Eckels that he needs to be extraordinarily careful, but Eckels remains excited and careless. He may understand the relationship between actions and consequences as Travis has explained them, but he cannot overcome his own emotional response to the dinosaur. Fear will overwhelm his reasoned understanding, and although he knows that “it wouldn’t pay for us even to touch the grass,” he will step from the path, setting sixty million years of events in motion that will lead to the election of a dictator in the United States.

He ran off the Path. That ruins us! We'll forfeit! Thousands of dollars of insurance! We guarantee no one leaves the Path. He left it. Oh, the fool! I'll have to report to the government. They might revoke our license to travel. Who knows what he's done to Time, to History!

After Eckels flees, terrified by the Tyrannosaurus, he returns to the time machine and hides. The hunting party, once they have killed the animal, returns to find him shivering on the floor. Furious, Travis threatens to leave him in the past, only to be talked out of it by Lesperance. Travis sees mud on Eckels’s shoes and responds with these lines.

Travis’s initial impulse and anger, tellingly, are not a concern foremost for the world. Instead, he sees that the consequences of Eckels’s actions might cost the company thousands of dollars in insurance money, as well as their license to conduct business. They are, ironically, unable to guarantee the safety of their clients, yet they do “guarantee no one leaves the Path.”

Travis disingenuously ponders the greater implications of Eckels’s misstep, noting that they have no idea what may have happened to time or history. Ultimately his anger is not justified at this point. As an employee of the company, Travis is complicit in the business and its risks. Although he clearly explained the consequences to Eckels, he shares accountability for what happens. Eckels’s carelessness, enabled by Travis and the venture itself, threatens the lives of the travelers, puts the company in danger of financial loss, and ultimately may alter the future. One single action, because of its multiple consequences, will haunt human beings for many years to come.