Eckels has come to the Time Safari office for a chance to travel sixty million years into the past and hunt a living Tyrannosaurus Rex. Eckels and several other thrill-seeking hunters pay ten thousand dollars each for a chance to kill a dinosaur. They are excited about the unique chance to experience a once-in-a-lifetime opportunity. After they travel back in time, the Safari guide, Travis, carefully explains the importance of remaining on the floating path at all times and warns the hunters about the severity of not obeying the rules. Unfortunately, Eckels panics when he encounters the gigantic, ferocious Tyrannosaurus Rex, and he frantically runs back to the Time Machine. When Travis and the other hunters arrive back at the Time Machine, he notices that Eckels has left the path and threatens to leave him in the past. When the men return to the present in 2055 AD, they discover that Eckels's mistake has drastically changed the course of human history.