Rocket Surgeon said:
I see the need for redemption, I see the desire for a last hurrah...
Same. I want them to finish off Indy with a movie on par with the original three, a movie which truly showcases Indy being a relic in his own time. It'd basically be Robin & Marion meets Mask of Zorro meets The Gunfighter. If Indy's going out, I don't want a "And they got married and lived happily ever after" ending. No. I want Indy to go out with a boom, not a whimper. To me, KOTCS ended on a whimper and the ending was pure fanservice to a portion of the fanbase. Sure he puts his hat on his head, reclaiming it...But he's married. He's now doomed to a boring rest of his life being married and an associate Dean. That's going out with a whimper. That's like putting a lion in a zoo; It's not the place he belongs. Indy's life is the field and adventuring. Surely he'd get bored. I don't see what's wrong with having him take the role of aging hero like Anthony Hopkins did in Mask of Zorro. Hopkins still had plenty of action scenes and was still a badass.
I picture some young kid pulling Indy out of retirement in search of an artifact, maybe the kid's heard of Indy's reputation and seemingly envisions himself like Indy--the legend. Indy at first seems reluctant but inside knows he's dying a slow death with marriage and fatherhood and teaching. It just isn't who he is. Marion maybe urges him not to go and it puts some sort of wedge between them and she doesn't show up again until later, having followed his trail. Mutt's away at college. Indy wants to show this young kid that he's still got it. That he isn't some irrelevant artifact himself. But there's a twist. Bad guys are looking for this same mystical artifact. It's got to be really shrouded in mystery, something EPIC. Something religious. The bad guys could be the Soviets again, or could be the last remaining Nazis attempting to revive the Third Reich, or a group like James Bond's SPECTRE--Except this group wants this mystical artifact to give them power. Maybe the government is involved somehow and part of Indy's going off on this adventure is the government asks him to--One last favor on his part and this young kid is assigned to work with him.
But the twist is somewhere along the line the kid doesn't respect Indy anymore and thinks he's better than Indy, or he's been working for the enemy all along and using Indy to lead them to the artifact...And he seemingly mortally wounds Indy. Maybe shooting him. Ondy, though mortally wounded, is able to finish off his enemies (except the kid) in a clever, believable way, protect the world. Maybe his death isn't made clear but he disappears into the mists. He doesn't necessarily have to die on screen; he could be seemingly mortally wounded and disappear--a legend, his true fate unknown.
Or, maybe as he's dying, the kid takes Indy's hat--Think of the film The Gunfighter--and either runs off to his own fate, or is killed by Marion at the last minute, who's been following Indy's trail all along, worried about him. He could die in Marion's arms, getting killed doing what he loves.
Think of films like the Mask of Zorro, Gunfighter, Robin & Marion, Carlito's Way, in terms of storyline of an aging/retired hero or expert in his field.
In terms of the tone, think of a Hitchcock film, or a dark, bleak sort of tone like The Misfits (Clark Gable's last film before he died, released in 1961. He died due just after the film finished due to a heart attack after performing all his own stunts out of boredom), or, an eerie, dark Twilight Zone-esque tone.
No more cheeseball antics like LC and KOTCS.