Bob Wilson becomes every visitor
While finishing a thesis arguing that time travel is impossible, Bob Wilson is urged through a time gate by a stranger, while a second stranger tries to stop him and a fight breaks out. The gate drops him thousands of years in the future, where a ruler named Diktor sends him back through the gate. He comes to realize that the stranger, the objector and Diktor were all himself at later points, and the story leaves him as Diktor, about to set the same sequence in motion for his younger self.