- Traveling through the world: The ancient "Dajing Dynasty" has just ended the civil war. The new emperor has ascended the throne but the foundation is unstable. Local forces are divided and productivity is backward. There is a small amount of unrecorded "thaumaturgy" (non-fantasy, similar to ancient mechanical art or the prototype of chemistry).
- Time travel opportunity: Two people were climbing a mountain to take pictures of the starry sky on a rainy night. They were caught in a rift in time and space by an abnormal lightning, and they carried a small amount of modern items with them.
