Why? Because she was in a YouTube video, that's why. I know how that sounds. You'll just have to read the book to see how it works out. Anyway, after her experience in the future, Debra, like Billy Pilgrim, seems to have come unstuck in time. She bounces around from the past to the future to the present, and it's no fun at all. I can't explain the physics of it, though Melton can, but things from the past are realer than things in the future. So in the future settings, Debra can dent steel by walking on it. In the past, even leaves or grass are hazardous to her.
Because changes to the past can affect the future, objects from the past are “more real” than anything from future times. When she is first taken into the future, Debra can punch through walls as if they are paper maché—but when she is sent into the past, leaves and grass hurt her feet like sharp gravel. Being in the past is hazardous to Debra—but in the future, she is hazardous to those around her. This is a refreshing change from the sort of story I mention above.
Like other Melton teens, Debra is smart and resourceful. When she figures out that she hasn't been told the whole truth of things, it's up to her to find a way to save the world. Does she? Well, sure. But I'm not telling. You'll have to read the book to find out how. Another great read from Melton.