Do you see an intersection of time and space in the story?

Explanation

The present era and the earlier time zones are effectively defined. The third level which depicts the old era is situated at a different level from the other two levels of this era. The facilities of the third level are of a different type from other floors. Even the locomotive is different. When Charley is at the third level his wife and friend are living in the present time. Similarly, when Sam had reached the previous era, Charley and his wife are still in the present era.