The episode starts off with Magica preparing her latest magic spell, which she intends on using to steal Scrooge's Number One Dime. The spell itself results in bringing Magica's shadow to life, much like if it were a ghost.
Meanwhile, at McDuck Manor, Huey, Dewey, and Louie play around with an instant camera that Gyro sent them. The camera also happens to feature an incredibly bright flash bulb, which the boys take advantage of to startle Mrs. Beakley and get a humorous picture of her.
Scrooge is at the Money Bin, in the middle of his spring cleaning (which involves cleansing any of his cash that happens to be dirty). The boys show up and take a picture of Scrooge, but the bright flash causes a few dollar bills that Scrooge was holding to lose their color. Scrooge scolds the boys, and considers getting somebody to perform an emergency dye job on his faded cash.
Meanwhile, Magica has arrived in Duckburg via a commercial airplane. After getting her bag of potions through customs without any trouble, Magica accidentally bumps into Vacation Van Honk (see Trivia below), causing his wallet to fall from his pocket. Magica's shadow attempts to steal the wallet, but Magica, not wanting to attract any attention, fights her shadow for the wallet before graciously returning it to Vacation Van Honk.
Later, a real estate agent is showing Magica around an old, run down house. It doesn't take much convincing for Magica to actually buy the house, since it's just the kind of place she wants. After settling into the house, Magica attempts to train her shadow into stealing Scrooge's dime by using an ordinary dime for practicing. Since the shadow can't grab the actual dime (or rather, the case it's housed in), it has to grab the case's shadow in order to move it around. Magica then scolds her shadow for breaking the case, and sends it off to Scrooge's mansion to steal the dime for real. But the shadow only has one hour to retrieve the dime before it disappears.
The shadow then creeps through the streets of Duckburg at night, and arrives at the mansion. After sneaking in by slipping under the front door, the shadow eventually finds the dime in Scrooge's bedroom. Before it can get away with the dime, the shadow runs into the shadow of a podium, causing the podium and the porcelain artifact it was supporting to fall over and break. Scrooge and the boys find the shadow, and chase it through the house into Scrooge's study. A mounted moose head falls on Scrooge's head, and the shadow it creates scares Magica's shadow into leaving through the chimney without the dime. With the shadow gone, Scrooge then concludes that shadow was caused by none other than Magica. Knowing that Magica will strike again, Scrooge and the boys prepare for another strike.
Back at Magica's house, Magica scolds her shadow for failing to steal the dime, and prepares to cast a spell that will make the shadow more powerful. When Magica goes into the closet to fetch some "Tickled Wiggly Worms" for the spell, her shadow locks her in. The shadow, sick of being bossed around by Magica, starts mixing together a potion which will permanently separate it from its master, in addition to making it stronger and more vicious looking. The shadow gloats to Magica, claiming how it will unite an army of shadows that will rule the world, and make every normal person a slave to the shadows. All that the shadow needs to complete the spell is Scrooge's dime.
Back at McDuck Manor, lights of all sorts have been set up, with Scrooge, the nephews, and now Launchpad patrolling the premises. The shadow, though it can't stand the light, puts up with it anyway and sneaks back into the house.
Magica, who apparently can't get out of the closet (even with her powers), is having a fit. Not knowing what else to do, Magica sends Poe out to get some help.
Back at Scrooge's, the shadow locates the dime, which is surrounded by a set of lights. The shadow manages to sneak up to the dime by passing through the electric cord of one of the lights, but is scared off by a shadow monster, which turns out to be a shadow puppet of Louie's hands.
Poe, who is flying around in search of help, shows up at the mansion, mainly because he remembers that Scrooge is also a victim of Magica's shadow. Scrooge is very reluctant to listen to Poe, until Poe explains to Scrooge that Magica is the only one who can dispel the shadow. That and the fact that Dewy and Louie remind Scrooge that leaving the lights on all the time will result in higher electric bills. Poe leads Scrooge, the boys and Duckworth all the way to Magica's closet, where Scrooge releases the witch. Magica explains that in order for her to stop the shadow, she'll need Scrooge's dime. Scrooge tells Duckworth to stay with Magica, while he and the boys will stop the shadow another way.
Soon Scrooge, the nephews and Launchpad are at a baseball stadium, where Launchpad has hooked up all the lights to a single switch, while Scrooge leaves his dime on the pitcher's mound as bait. The nephews are wary of Scrooge's plan, thinking that maybe working with Magica would've been a better idea, but Scrooge disagrees. When the shadow comes to steal the dime, the lights don't function properly, and soon Magica's shadow summons more dronish shadows of the witch (these ones more normal looking the original disfigured one). While shadows play keep away with the dime with Scrooge, Launchpad unintentionally reminds the nephews of the dark, which prompts them to turn off all the lights. This weakens the shadows, which do need some some light in order to survive.
The shadows chase Scrooge, the boys and Launchpad through the city, when Scrooge opts to head to the Money Bin, which is air tight. After escaping a run in with Magica's shadow, Scrooge and Co. meet up with Magica at the Money Bin. Magica reminds Scrooge that she'll need his dime to reverse the spell. Scrooge refuses at first, until his family and friends demand that he give in and let Magica have the dime (or at least borrow it). Scrooge and Launchpad go outside and pretend to give up to fool the shadows, who enter the money bin and find their way into the vault, where Magica is preparing to reverse the spell.
Magica and her shadow get into an argument, where the shadow claims that it can never be defeated. Although Magica is able to dispel the drone shadows with the dime in hand, the main one will take more strength. The nephews then each use a camera of Gyro's simultaneously, the flashes of which put an end to the main shadow. After celebrating the defeat of the shadows, Magica decides to run off with the dime, but is scared into dropping it when she sees that her disfigured shadow has returned. It turns out that this shadow was a just a shadow puppet of Dewey's. As Magica flees, Scrooge remarks that the witch is still afraid of her own shadow.
- This episode was the first to feature the current cat screech sound effects that would later be released on sound effects libraries by Hollywood Edge.
- Launchpad first appears in the second act of the episode, but he doesn't speak until the third act.
- DuckTales: Volume 1