Plot synopsis
Four children go into a mine looking for lost gold. They discover that the mineshaft is a time travel portal that brings them out at the same location but in the Old West. They can move freely between the worlds by climbing up and down the shaft.
Soon, they find that their school principal has been moving between these worlds for a while and has become the town sheriff in the Wild West.
He is about to collude with three bandits who are in town to rob the bank. So, with the help of the elder brother of one of the boys, they try to stop him from changing history.
My comments
As the children go back and forth, they are able to change the past, but this has little effect on the present that they return to. Therefore, this would indicate that the timeline converges each time they change the past. It is the type of timeline that the characters believe is in place that needs to be identified.
Summary of time travel
The children are afraid that their school principal is about to make a significant change to history, which will make a difference to the present when they return (as represented by the dashed line on the diagram below).
This shows that they believe in a model of time with a double-well timeline, even though the timeline eventually converges back to the original one.
They use the information that they bring from the past to their present to change the future, which means that it is open.
Category of time travel
Fantasy: finding portals.
Model of time
Open past, open future with a double-well timeline.
