"Sweet Duck of Youth" is the twenty-eighth episode of DuckTales.
At nightfall, Launchpad is bringing Scrooge back to his Manor after taking him around looking for a lost mine. After the helicopter has landed and Scrooge says a few things to Launchpad about how back when he was Launchpad's age he could not be talked into coming home at this time. Launchpad makes the comment "Of course not Mr. McDee, when you were my age, airplanes and helicopters had not been invented yet!"
Then Scrooge looks toward his Manor and notices all the lights are turned off and that someone is using a flashlight to get around in one of the rooms on the far end of the house from where the helicopter landing pad is at. Launchpad suggests for Scrooge to go inside the back door while he sneaks around to the other side and comes in another way. Scrooge creeps into his house and up the hallway, and he starts overhearing people quietly talking about something. Scrooge is thinking that he has found the burglars.
As he busts open the door, he steps on a skateboard and rolls across the room, falling into a table and knocking over a bowl of fruit punch. The light turns on, and Scrooge sees what's going on: Revealed are Gladstone Gander, Vacation Van Honk, Mrs. Beakley, Huey, Dewey, Louie, Webby, Gyro, Duckworth, and Doofus, all standing together on one side of the room. Launchpad sticks his head in trough the window and says "See, I told you I would get him here in time! ...Happy Birthday Mr. McDee!" Everybody else chimes in and shouts "Happy Birthday!" to Scrooge.
They have the birthday cake ready, and there are at least 60 candles on it. Scrooge tries to blow them out, but he can't. So Launchpad blows them out for him. Scrooge looks over and sees a very large wrapped gift that the others have all pitched in to buy for him. When Scrooge walks over to unwrap it, he says "I hope it is a nice new office safe!" But when he unwraps it, it is a rocking chair. Scrooge starts really feeling down because of his age.
Mrs. Beakley suggests for him to start having some fun with them, but Scrooge says "Madam, at my age, fun can be hazardous to your health!", to which Mrs. Beakley replies "Face it, Mr. McDuck, unless someone finds the Fountain of Youth, everyone will age!" Hearing those words Scrooge suddenly runs to his Library and picks up a book that tells about The Fabled "Fountain of Youth". He proceeds reading information out of the book, giving the details that a Spanish explorer had searched the Okeefadokie Swamp for the fountain some 500 years in the past, and that he had gone into the swamp, never to be seen again.
One of the Nephews makes the comment "Maybe he did come back out, but nobody recognized him!" That gives Scrooge the idea to have Huey and his brothers, along with Launchpad, to pack up supplies into the helicopter and head for the very swamp that the book said the Spanish man had disappeared in.
When they arrive and land in the swamp, Launchpad realizes he landed in quicksand, so Scrooge and the boys have to lighten the load and get out of the helicopter in order for Launchpad to be able to lift off again. The boys got out fine, but when Scrooge tries getting out, the box he put his feet on starts to sink, and so he uses his cane to hook onto the helicopter as Launchpad starts taking off. As they are getting back up in the air, about to land off to the side of the swamp, a stranger wearing an antique suit of armor fires an arrow from a crossbow, hitting the rear rotor of the helicopter, causing it to crash.
Scrooge lands in one area, while Launchpad crashes in another area near water. Huey and his brothers run over to Launchpad, asking him "Where's Uncle Scrooge?" Launchpad tells the boys that their uncle had bailed out just before the crash. One of the boys notices the arrow stuck in the rear rotor and deducts that someone had shot at the copter. Then Dewey asks for the Junior Woodchucks Guidebook, and he, his brothers, and Launchpad take the main body of the copter and rebuild it into an airboat so they're able to get around the swamp, searching for Scrooge.
As Scrooge is wandering around, he starts feeling a pain in his legs that is both a sign of his age and an indicator that tells him that a rainstorm is coming. So, Scrooge takes some tree limbs and other things to construct a makeshift shelter to shield him from the rain. All of a sudden, the mysterious person in the antique armor comes up from behind and destroys the shelter, prompting Scrooge to run until he finds a cabin in the middle of the swamp, banging on the door for help.
The person in the armor follows him there and captures him using a fishing net. On the other side of the swamp, Launchpad tells the boys to set up a tent while he keeps searching for Scrooge. After the boys get done, one of them says "I am worried because he can not take care of himself." One of the others adds "Poor Uncle Scrooge!" to which his brother replies "I was talking about Launchpad!" The third brother agrees, "Uncle Scrooge can take care of himself, but nobody can keep Launchpad out of trouble — especially himself!"
As Launchpad is searching around the swamp, using a search light, he notices a stranger standing on the shore, wearing the armor of a Spanish explorer. Launchpad wonders out loud "That Spanish guy can't still be around in this swamp; he would have to be 500 years old. Or a Ghost!" Then an arrow hits the side of the boat, causing it to sink, and Launchpad starts shouting "Help!, I can not Swim!" A fishing net is thrown to him.
Just a short while later, the very person in the Spanish armor attacks the tent of the boys, who decide to follow him. Huey and his bothers notice the stranger going into a cabin. They peek through the window and notice Uncle Scrooge and Launchpad, both tied up by fishing nets. Then they see the man in the armor taking off his helmet, revealing him to be an elderly man who looks to be in his late 60s to early 70s.
After the elderly man goes to bed, the boys sneak into the cabin to try to free their uncle and friend. When one of the boys causes something to fall, the elderly man wakes up, heading towards the room. The boys hide in the Spanish armor, and as the elderly man appears in the door, the boys act as if they are the ghost of the Spanish explorer who was the original owner of the armor. They scare the elderly man, and when he causes a piece of firewood to roll out in front of them, the boys trip and fall into the man, knocking him out for a short while.
By the next morning, the elderly man tells Scrooge and the others how he had been searching for the fountain since he was in his mid 30s. Dewey and his brothers notice a riddle in the armor, and with a hint from Scrooge they figure out that there is a hidden storage place in the helmet, that contains the map to the Fountain of Youth. So, Scrooge and the elderly man make a deal that they would split the profits 50/50 after they find the fountain.
They all follow the map to where it leads, and they discover a dried up fountain on the surface, but when Scrooge jumps up and down, he causes the area on one side of the fountain to cave in, and when all of them fall underground, they wash downstream to a place with two waterfalls, that come together in one lake.
When Scrooge reaches for his hat that is floating toward him in the water, he looks down and sees himself looking younger. The other man looks down, and sees himself younger as well. Then the boys look, and they see themselves as eggs that have not hatched yet. But Scrooge realizes that neither of them have really changed. The elderly man realizes "The Fountain of Youth does not make you young, it only makes your reflection young!"
He gets so upset that he had spent over 30 years of his life searching for a fountain that turned out to be a hoax of what he was lead to believe it was. Scrooge helps him back up and out of the cave, and offers him a full paid trip so he could enjoy the rest of the world during the remaining time he has left to live.
By the time they land back in Duckburg, Launchpad is worn out and feels much older than Scrooge, who tells Webby that he did not find the fountain that he was searching for, but that he had found himself. Mrs. Beakley remarks that Scrooge appears 20 yaers younger than before, as Duckworth drives them all back to McDuck Manor.
- Scrooge says "You are only as old as you feel", paraphrasing Muhammad Ali.
- When Scrooge, the elderly man, and Launchpad are looking at their reflections, they can be heard talking, but their reflections do not move their breaks.
- DuckTales: Volume 1