The kids and Launchpad work together to capture a mystical money shark while Scrooge attempts to better his public image with a televised interview.
Lena shares an awkward moment with Donald Duck in McDuck Manor as they await the return of Scrooge, the boys, and Webby from their latest adventure. The five soon return, having apparently grown a giant beanstalk and obtained some treasure from the top. Scrooge soon has all the spoils-including those taken by the boys-prepared shipped off the Money Bin. Mrs. Beakley then informs him that he has an interview scheduled with Roxanne Featherly by the Board of Directors in response to Scrooge's reckless behavior and the damage it has done to Duckburg.
Lena slips a strange red jewel into the treasure, which upon landing in the bin dissolves and begins spreading a magical glow throughout Scrooge's valuables. Lena is then revealed to be joining Webby for a sleepover, as well as planting the jewel on Magica's orders. The pair are attempting to steal the Number One Dime, with the jewel creating a "hunter" to seek it out. Webby then gives Lena a friendship bracelet before showing her her board. After explaining Scrooge's hatred of magic, she also shows Lena a magic book she smuggled into the house.
The boys arrive and try to initiate a pillow fight against the girls, but are swiftly and painfully defeated. On Dewey's suggestion, they head off to the bin while Beakley tries to help Scrooge get ready for his interview. At the bin, Dewey dives in only to be swallowed by the hunter: a monstrous shark with a body composed of gold coins. Huey and Louie rush back to the mansion and inform Lena and Webby, and Lena and Louie's insistence set out to deal with it themselves. Launchpad joins in, having somehow sensed Dewey's peril, and they steal Donald's Houseboat and airlift it to the bin.
Lena has another conversation with Magica, who reveals that the creature is called Tiffany and that it will continue growing as it prepares to seek out the dime. The group attempts to bait the shark, only for Huey and Louie to be swallowed as well. Scrooge begins his interview, and it proves to be just as grueling as Beakley warned him. Webby attempts to deal with the shark using magic, while Launchpad's attempt to crash the boat into the shark results in the boat being swallowed with him aboard.
Scrooge's interview continues to deteriorate as Glomgold is brought in as a guest and their antagonism makes Scrooge look worse than ever. Webby joins hands with Lena in an effort to stop the creature, and begins tapping into Lena's powers unknowingly. Lena breaks the connection before the spell can be completed, and the shark breaks out of the bin and lands on the bridge to Duckburg. It then appears on the news, and Scrooge breaks away from his interview to deal with it.
After briefly questioning Lena's reasoning behind stopping the spell, Webby spots the arriving Scrooge. The creature draws Scrooge's dime into its mouth, and Scrooge's attempt to retrieve it gets him swallowed. Webby then attacks the creature herself, while Magica orders Lena to retrieve the dime. However, the creature goes after her, and Webby knocks her out of the way. Webby is swallowed, and Lena soon joins her in the beast's throat, where Webby asserts that their friendship is more important to her than Lena's behavior.
Magica is stopped from grabbing the dime as Lena casts the spell herself, destroying the money shark. She and Lena reunite and reconcile, while the scattered coins of the money shark are taken by various denizens and criminals of Duckburg. Scrooge succeeds in retrieving his dime, and Magica becomes furious at Lena. Lena expresses her own fury towards Magica, but is unable to leave her service. Magica then reminds her that only she can grant Lena's wish for freedom, and the teenage duck sadly removes the bracelet Webby gave her. Later, Launchpad wakes a sleeping Donald by dropping his houseboat in the pool, much to the latter's shock.