Let's set the scene: Indiana has just watched Elsa plummet to her death because she couldn't shake her obsession with the Holy Grail. Now he's dangling off the same cliff while his dad pleads with him to take his hand and forget about the Grail. "Indiana, let it go," Henry says quietly. Indiana does as his dad says.

There's more going on here than Indiana coming to his senses and avoiding death by crevasse. First things first, Henry calls Indiana "Indiana." That's huge. Before this point, Henry's constantly and only called Indiana "Junior," because, as Henry explains to Sallah, "That's his name: Henry Jones, Jr." This ticks Indiana off. He wants to be called the nickname that he gave himself (in loving tribute to their family dog, no less), so when Henry calls Indiana what he wants, it shows care and consideration.

Second, when Henry tells Indiana to "let it go," he's not just talking about the Holy Grail perched precariously below. He's also talking about the resentments and anger toward his dad that Indiana's held on to since he was kid, when Henry was too absorbed by his own obsession with the Holy Grail to take Indiana to Chuck E. Cheese or throw down on the Xbox.

Basically, Indiana's spent his entire life harboring a handful of grudges against dear ol' Dad. When Indiana finally lets them go, as Henry suggests, and takes his dad's hand, they can start repairing their relationship.

Indiana isn't the only one who wises up at the end of the film, though. After Henry pulls him to safety and they tell the old knight to peace out, he and his dad have the following exchange:

HENRY: Elsa never really believed in the Grail. She thought she'd found a prize.

INDIANA: And what did you find, Dad?

HENRY: Me? Illumination.

Dude's not talking about lights. After almost losing his son to the Holy Grail, Henry realizes what a cruddy dad he's been to Indiana because of his own preoccupation with the Cup of Christ. Indiana wanted guidance and structure that Henry didn't provide, and the lightbulb's finally gone off above Henry's balding head.

Ultimately, Indiana Jones and the Last Crusade ends with a reconciliation. Indiana's started to release old resentments. Henry's realized that his kid wanted him to be around more. Lines of communication are finally open, and the two men are ready to ride off into the sunset and reboot their father-son relationship.