Raiders_of_the_Lost_Ark remains as one of the best action-adventure movies in history.
https://en.wikipedia.org/wiki/Raiders_of_the_Lost_Ark#Plot
https://www.imdb.com/title/tt0082971
Indiana_Jones_and_the_Kingdom_of_the_Crystal_Skull ends with a classic interdimensional Sci-Fi twist.
https://en.wikipedia.org/wiki/Indiana_Jones_and_the_Kingdom_of_the_Crystal_Skull#Plot
The implication being that advanced ET life forms might not just be from a place within this universe, but potentially from another universe, realm or dimensional plane of existence.
