Cat, a fugitive from a parallel Earth ruled by aliens, lands on "our" Earth in the middle of a freeway, causing an accident. She is slightly injured, and wakes up in the emergency room of a hospital, where Thomas, a doctor, takes care of her. He finds out that Cat is fleeing a group of servants of the Dark Lord. They hitch-hike to the nearest Doorway to another parallel world.They arrive in an alter-Earth where petrol has disappeared. Their adventures continue as they are still chased by villains. At last, they stumble through another door and land on top of Mt Rushmore. But the four faces that are sculpted on it show that Thomas is clearly not back home yet.