- Armed with his dad's Grail diary, Indiana heads into the cobweb tunnel of decapitation. He keeps repeating a clue: "Only the penitent man will pass." Henry repeats it, too—you know, as he lies on the ground bleeding to death.
- Indiana correctly deduces that the clue means he needs to be humble before God. When the ghostly presence once again moves the cobwebs, Indiana kneels before it. A giant saw blade passes over his head. He's passed the first challenge, and yells as much to the crowd he left behind. Everybody's happy.
- The second challenge is all about the word of God, and Indiana comes upon a floor made of stones with letters on each one. He figures out that he should step on the letters that spell out "Jehovah." Way to go, Indy! He doesn't, however, remember that in Latin, "Jehovah" starts with an I. He eagerly steps on the J stone, and his foot plunges through the floor. Then he remembers his Latin, and he's on his way.
- At the third challenge, Indiana faces a giant chasm. There's no way he could ever come close to jumping across, and he eventually realizes that it's a leap of faith. Indiana takes a giant step off the edge and Boom! There's an invisible bridge. He slowly walks across, and before he moves on, he throws some sand across the bridge so he can find his way back more easily.
- Challenge #4 is one seriously old knight sitting in a cave filled with a wide assortment of grails. The ancient knight raises his sword to strike Indiana, but it's so heavy that he topples over.
- The knight introduces himself to Indiana as the third of the three brothers who were left in charge of guarding the Grail. Indiana does the math and realizes that that makes this dude over 700 years old.
- The old knight tells Indiana that he's happy to relinquish his post. 700 years is a long time to sit in a cave by yourself.
- Just then, Donovan and Elsa show up.
- Donovan's all, "But which Grail is it, ma-an?"
- The old knight tells Donovan he has to choose. Elsa says she'll choose for him, and hands him one of several ornate gold grails. Donovan holds it up and says it's beautiful. Indiana looks like he wants to barf.
- Donovan takes the Grail over to a fountain and fills it with water. He's positive he's made the right choice, and he drinks from the Grail. Everyone watches with bated breath.
- Donovan starts aging fast—like, turning-into-a-skeleton-in-under-ten-seconds fast. He holds on to Elsa as he wastes away, and she screams in terror.
- "He chose…poorly," the old knight deadpans.
- Indiana and Elsa go back to the grails. Elsa says the Holy Grail wouldn't be made out of gold—which suggests that she set Donovan up. This girl is cold.
- Indiana chooses a plain cup, citing that it looks way more like the cup of a carpenter than anything gold or fancy.
- Indiana takes this cup to the fountain, fills it, and drinks. The old knight tells Indiana he chose wisely. Also? He tells him the Holy Grail can't leave the building. More specifically, it can't cross the giant seal in the entryway of the building, back out where Henry, Brody, Sallah, and all of Donovan's goons are.
- That's the price of immortality: you never die, but you have to live in a cave that we're pretty sure no pizza places will deliver to for the rest of time.
- Indiana fills the Grail with water and runs it out to his dad. He helps him drink from it, and then he pours some of the water on the gunshot wound, which promptly disappears.
- Henry takes the cup from Indiana and looks at it. This is what he's spent his whole life looking for. Then he sets it down on the ground as Indiana helps him to his feet, and Elsa picks it up.
- Elsa's giddy—kind of unhinged, really—about holding the Holy Grail, and she starts heading for the exit. Indiana tells her to chill out. He reminds her that the Grail can't cross the seal.
- Elsa ignores Indiana and steps across the seal. The whole place starts to shake and quake with the force of a monstrous earthquake.
- The floor splits open, Elsa drops the Grail, and it falls into the crack. Then Elsa does, too.
- Indiana tries to pull Elsa to safety, but she spots the Grail on a nearby ledge. She's gotta have it. Indiana needs her other hand to save her, but she keeps reaching for the Grail with it and falls into the abyss.
- After Elsa falls to her death, Indiana slips off the cliff and Henry grabs his hand. Henry demands that Indiana give him his other hand, but Indiana reaches for the Grail. He thinks he can reach it. Déjà vu…
- Pleading with his son to stop being a greedy moron, Henry calls Indiana "Indiana" for the first time in the movie and gets his attention. He tells his son to "let it go," and we have a feeling that he's talking about more than just the Grail.
- Indiana gives Henry his other hand, and Henry pulls him to safety. The building continues to collapse around them.
- Just as they're about to hit the road, Henry sees the old knight. He stares. The old knight waves. He looks sad. Henry and Indiana run for the exit and make it outside safe and sound.
- Henry tells Indiana that Elsa never believed in the Grail. She thought it was a prize. Indiana asks his dad what he found on his quest for the Grail, and Henry says illumination. Aw. Does anybody else smell forgiveness?
- Sallah asks why Henry keeps calling Indiana "Junior." Henry explains that Indiana is Henry Jones, Jr., and that the family dog was named Indiana.
- Indiana says he has a lot of fond memories of that dog.
- Sallah thinks this is just about the funniest thing ever and can't stop laughing.
- Brody takes off on his horse, attempting to lead the way back to civilization, but struggling mightily to just stay on his steed.
- Indiana, Henry, and Sallah follow, and the four men literally ride off into the sunset.