I think that's what I'm getting at. You couldn't do it as a straight re-hash of FOA because it wouldn't fit now. Even if you did go the prequel route there'd be no point bothering with a different love interest because we know now that noone can compare with Marion.
I'd personally love to get the focus back on Indy more and reduce the ensemble 'gang's all here' vibe. The problem would be getting Indy, Mutt and Marion all on an adventure in a way that doesn't feel like the Mummy series. You probably can't actually. You can't have one of them being kidnapped because that's been done in both the last sequels. Unless Indy gets himself in trouble and they need to help him but not too keen on that either.
I'm thinking opening set on a sinking ship in the middle of the Bermuda Triangle. Sharks circling the boat (the Paramount Dissolve would be to a shark's fin as it slices through the waves - a nod to Jaws lol). Indy and his rival (who would be a younger, ruthless and cuthroat version of himself in many ways) out cold in the wreckage of the sinking boat. The boat sinking fast. Indy wakes as the water laps at his feet. Blood from his cuts dripping into the water. CUt back to the sharks. We could put some henchmen on here (at least one) who can fall into the water and get munched in a feeding frenzy. FOr some reason the idea of INdy crawling out over a mast to get from sinking ship to dry land appeals - Indy has to be careful with his weight because the mast is bobbing into the water. You could have a moment where his hat drops into the water. He can't lose his hat. He reaches down to grab it, fingers tantalisingly close to the hat-- A sahrk comes out of the water a la the old "chum some of this" moment in Jaws. If we use a great white, it sticks its head out of the water, which they do in real life. Indy finds himself face to face with killer shark much like he did with the Cobra. Or Mako's are known to jump out of the water onto the boat. SHark jumps in. Indy jumps out-- realizes mid-jump the water is teh last place he wants to be. Just catches onto the rigging on the side of the boat. Now he's stuck on the side of the boat, sharks circling in the water below. A mako shark snapping on deck above...
Possibly Indy escapes that scrape by just making it to a desert island. Attacked by Cannibals maybe. Traps. Temples. Possible volcano. If you did decide to go to Atlantis you could have him finding an artifact that the Cannibals worship. When he gets it back to Marshall he realizes it has special powers (contains clues to Atlantis) and the Commies and his rival are after it and him. Maybe he has to take Mutt and Marion because he knows full well that the Commies will use them as leverage against him. The race is on. That seems to make sense.
Yeah, that's it...Indy deals with the Commies that come for him but realizes with dread that they'll be going for Marion and Mutt so he has to race to get them out of there. We can make these Commies a bit meaner than the last bunch. Fortunately we know that if there's one family you don't want to mess with it's the Joneses. YOu could have a great Indy fight through Indy's house that completely trashes it, artefacts and all. Could be great humour as well as some classic Indy brawling, banter and flashes of Spielberg visual wit.
Not sure. Just some random ideas.