The Nazis want to get the Ark of the Covenant, and are being helped by unscrupulous archaeologist Belloq, who may not be as good as Indy, but sure is unscrupulous. Indiana Jones actually fails to stop the Nazis, who are stopped by magical powers from God. Oh, and there's a woman involved.That doesn't sound like too much fun, but it helps to emphasize the action of the story, which is actually instigated by the Nazis. Similarly, while the movie looks simple, there's some interesting twists here; for instance, we probably want to say that the Nazis are the antagonist, but then, what of Belloq? In some ways, he's more the dynamic relationship character: The Nazis want the Ark for its power, Indy wants to keep the Nazis away from the Ark, and Belloq wants the Ark for... Well, it's unclear: sometimes he sounds like he wants the historical Ark, sometimes he sounds like he wants the mythological Ark. But this is precisely the journey that Indy has to make, from historical to mythological interest.
So in that form, we can see what the protagonist and antagonist are fighting over, and where the dynamic relation character fits. The short, rough story of my version of Indy 4 is
Soviet agents use Indy in search for alien technology in America, in race against cuckoo archaeologist/researcher and protege he no longer believes in. Indiana has to recognize his passing and the potential skills of protege in order to stop dangerous organizations from taking control of power beyond their understanding.Or something like that--there sure do seem to be a lot of antagonist figures here, potentially. One danger of brainstorming like I did yesterday is that I end up with lots of ideas that seem cool; as Tina Fey notes in Bossypants, one of the biggest tasks of the creative person is to prune back that creativity.