Scrooge is informed that next week, Duckburg is celebrating the 50th anniversary of when he first arrived there, and finds himself wondering why anyone would care as to when he arrived. Donald then tells him that the Golden Jubilee celebration includes a contest to find the best suggestion for the perfect gift for Scrooge. Scrooge, however, is not at all keen on the idea, and refuses to admit to Donald or Huey, Dewey and Louie what his desire would be.
Meanwhile, the Beagle Boys visit Gyro Gearloose, claiming to have reformed and offering to pay him to build a giant suction device that they claim they will be using to harvest oranges; in addition to this, they buy a bike-saucer using money supplied in bags baring the initials "F.G." (which they say is a federal grant). Over in Cairo, Italy, Magica De Spell uses money from the same supplier to purchase a projecto-gem, a transmutation wand, and some global-transport dust. She then uses the last of those to teleport to meet with the Beagle Boys and the money supplier, Flintheart Glomgold; they have all teamed up to take down Scrooge at the celebration and achieve their own goals.
At the day of the Golden Jubilee, Scrooge refuses to take part in it, especially since all of his employees have taken the day off, but Donald suggests he go to the party and get it over with, so he does, leaving Donald in charge of guarding the Money Bin. Shortly after, though, Donald gets a visit from the Beagle Boys disguised as the nephews and other regulars, and finds their activity suspicious. Down at the festival, Huey notices that the host is actually Glomgold in disguise (by looking at his shadow) and tells it to Scrooge, who realizes that Magica must be behind this. He and the boys rush back to the Bin and collide with Magica (who was using the projecto-gem at that moment), causing her transmutation wand to break, which as a result transforms the Beagle Boys into looking like hybrids of them and the ducks they're disguised as. One of the Beagles then steals the security grid key from Miss Quackfaster, allowing them to use the invention they had Gyro build to tear open the Money Bin and suck out all of Scrooge's money. Immediately following this, the Beagles, Glomgold, and Magica escape into the suction machine themselves, with Scrooge following behind.
Down below, Scrooge finds himself in the remains of the original Duckburg, which has since gone underground when the city's new construction went above the original street level. He soon finds the bad guys celebrating their success in Coot's Emporium along with the mastermind behind the scheme, Blackheart Beagle. When Scrooge breaks in and figures out that Blackheart is planning to transport the money out through the abandoned subway tunnels, Blackheart boasts that he's going to make sure nobody bothers to follow them by blowing up Duckburg. The Beagles continue loading the cash onto their train and leave Magica to guard Scrooge. Scrooge, however, manages to find old telephone lines he had installed 47 years ago, and starts kicking at them in morse code. Back up above at the festival site, Donald manages to rally the citizens into helping find and rescue Scrooge; when the nephews try to call Junior Woodchuck Headquarters, they pick up Scrooge's morse code message and translate it. Recognizing Coot's Emporium as her father's general store, Grandma Duck leads them there.
Back underground, Magica gloats to Scrooge that she now has the Number One Dime, but Scrooge tells her that the spell she intends to cast with it will no longer work now that he's lost everything, and offers a suggestion to her if she'll give the dime back. Soon after, as Blackheart starts gloating to Scrooge himself, Donald and the nephews ambush him, allowing Scrooge to go after the Beagles' train and stop it. When Blackheart threatens to detonate his bomb, Scrooge seemingly lets the train go off, but then reveals that the track on which it's traveling was condemned two years after he built it because it couldn't support a loaded train. The Beagles' train falls into the sewers as a result, so Blackheart flees, escaping on the bike saucer that his grandsons bought from Gyro.
Leaving Donald and the boys behind to disarm Blackheart's explosives, Scrooge snags onto Blackheart's escape vehicle, causing him to crash onto the statue of Cornelius Coot. Blackheart finally pushes the button on his detonator, but by this time, Donald has disarmed the bomb, rendering it useless. Blackheart then attempts to escape on his bike saucer, swearing that he'll return, but Gladstone Gander manages to help by asking the police to put a reward on Blackheart's head; a lucky wind then comes from Gladstone and throws Blackheart off course, getting him snagged in a banner and dropping him at the feet of the police. Elsewhere, the other bad guys climb out of the sewers. Magica then transports herself and the Beagle Boys to the Valley of the Limpopo, where they get to work robbing Glomgold's Money Bin, much to Glomgold's dismay.
A few days later, just as things are returning to normal in Duckburg, Scrooge gets a surprise visit from Goldie, which Donald and the others had planned for before the contest was even announced. Goldie says she was brought here to give Scrooge "a little something... special" and then promptly gives him a kiss, which he initially doesn't seem to like. As soon as she leaves, though, Scrooge sighs happily to himself, for seeing her again was what he really desired the whole time.