What does travis tell Eckels they are going to do to him?

Travis tells him leaving the path will result in him being left behind in the past. In Ray Bradbury's "A Sound of Thunder", a hunter from the future, Eckels, makes use of a time machine to go back to the past and hunt Tyrannosaurus Rex. Travis, the hunting guide, warns all the hunters in the party it is essential they stay on a floating path to avoid any disruption of the environment. Eckels falls of the path in a panic and as a result is threatened by Travis.