Plot synopsis
Rufus travels back from the future in a telephone box to convince two teenagers, Bill and Ted, that they have a crucial role to play in the future of mankind.
He tells them they must travel backwards through time in one of these phone boxes. They need to kidnap famous people from the past, such as Socrates, Napoleon, Billy the Kid, Joan of Arc and Abe Lincoln, etc. If they bring them all back to the present, they can be part of their high school history presentation.
They need to pass this with an A-grade, or Ted will have to leave town to attend military school. But if this happens, they will not be able to form their band, Wyld Stalyns, and make a real impact on the world.
My comments
Rufus comes back from the future to change our present. Though from his point of view, he begins in the present and arrives in the past.
Summary of time travel
If Rufus had not made the trip, then the Wyld Stalyns would not have formed and the timeline would not have followed the same path. So without his intervention in the past, the world he came from would not have existed.
This creates a predestination paradox, which means that Rufus was always meant to come back and intervene. Without the help of his time machine, it is extremely unlikely that boys would have gained an A-grade in their high school history presentation. Therefore, the timeline must be fixed with a causal loop.
Category of time travel
Science fiction: a time-travel vehicle.
Model of time
Closed past, closed future with a fixed timeline and a causal loop.
