This seems like the obvious option to me. Chris Pratt as Indy's illegitimate son. Indy hears from some of his old contacts around the world about a treasure hunter who's stealing artifacts. A genius for navigating his way around traps and disasters. Indy goes on the hunt and eventually finds Pratt, and they get into a yelling match, Pratt calls Indy a dick, Indy says sarcastically do you kiss your mother with that mouth, Pratt says 'Coming from the jerk who knocked her up and abandoned her, that's pretty rich' where it comes out that Pratt's mother (Callista Flockhart) is Indy's ex, but Indy had no idea she got pregnant. Exposition point in the shouting match comes out that Flockhart has been kidnapped by Nazi's who found out that Pratt is Indy junior and are demanding that Pratt supply them with rare artifacts for a nefarious plot to launch a new Reich. They're how Pratt finally knows who his father is and why he's so pissed after his mother keeping it a secret his whole life. Pratt has a plan to double cross them and rescue his mother, but is having trouble getting the last artifact. After some grudging reconcilliation happens, Indy asks pratt if he's an archaeologist and that's how he's so good at finding these artifacts. Pratt says no, he's an engineer - he's just gotten this far because archaeology is easy. Indy grumbles about how if it's so easy how come he hasn't found the last artifact. Then they rescue flockhart and make hilariously sarcastic jabs at each other while they outwit the Nazi's and return all the stolen artifacts to their rightful owners. During the outwitting the nazi's there's a long and fanciful sword fight between Chris Pratt and a baddy before Indie looks disgusted and shoots the baddy in the face.