Donald and Lina are expecting the return of Scrooge and the company from another expedition. Donald tries to break the long pause when the noise from the hall announces the return of the travelers. While Donald helps his nephews to bear a heavy coin, Mrs. Cluvdia reports to Scrooge that the Board of Directors is concerned that his treasure hunt is doing more harm than good. Scrooge dismisses, assuring the maid that all his efforts are only for the good of the city and goes to rest. Lina, meanwhile, creeps up to the treasure trolley and lays a magic ruby and almost comes across Ponochka, who appeared with the statue. She greets her friend, enthusiastically telling what a fun night awaits them, and the girls run upstairs. Some time later, the handyman takes the mined gold to the Vault, the thrown gem is activated, filling the entire space with red light.
Having risen into the room of Ponochka, Lina locks herself in the bathroom, where Magika pops up: she demands to concentrate on the task, however, Lina intends to just wait and have fun with Ponochka. While Lina is arguing with her aunt, Ponochka makes friendship bracelets for herself and her friend. Ponochka shows Lina the “Merlock Spell Book” she smuggled in secret from Scrooge, the girls start a pillow fight when Billy, Willy and Dilly run into the room, but the girls quickly get the guys out of the room. Then Willy offers to go to the Scrooge Vault and dive. At this time, Scrooge is preparing for an interview with Roxanne Featherly.
The boys, meanwhile, get to the Vault, they make their way inside to the safe. Willie gets ready to take the triple-flip jump, Billy reads the hymn, and Willie finally jumps and the shark suddenly jumped out and eats it. The brothers run away in horror, get on their bikes and in a few seconds get to the house. Lina and Ponochka are busy with a board game, when frightened Billy and Dilly burst into the rooms, they try to explain what happened, and Ponochka realizes that Willy has eaten a shark. She offers to turn to Scrooge, but Lina dissuades and offers to figure out everything herself, just in time on the doorstep of the room ZigZag appears, who felt a threat to Willie. For this operation, they borrow a boat from Donald.
Upon arrival at the Warehouse, the boat is lowered down and landing on it. Billy decides to lure the shark, and Dilly with a heavy heart throws the future inheritance overboard. Lina at this time retreats into the cabin of the boat when Magica reappears, praises her for the idea of feeding the Scrooge Tiffany family and reports that she will grow and become angrier as she searches for the Scrooge coin. Lina has no choice but to wait, she gets out onto the deck, where Billy and Dilly figured out a way to lure the shark with a catch on the bait. The monster swallows the bait, but the brothers cannot hold it and fall into the jaws of the monster. Then Ponochka tries to find a way to defeat the shark using the spell from Merlock’s book, Lina does not share her ideas, then Zigzag decides to ram the monster. He directs the boat to meet the monster and she swallows the boat as a whole, the girls have time to jump out at the last moment. Ponochka persuades Lina to use their friendship magic, but Lina resists and does not allow her to use magic, fearing that she will be exposed. Tiffany, having made the jump, gets out through the window, and growing noises, gathers in the city.
At this time, an interview takes place at Scrooge’s house, where he has to answer the journalist’s uncomfortable tricky questions and communicate with Glomgold when Roxanne begins to transmit news from the Scrooge Vault and the new danger that has hit the city. Having escaped to freedom, a money shark scatters the state of Scrooge around the district, where local fishermen and Flinthart Glomgold rushed. Scrooge also breaks down to save his savings, he drives away the locals, while the shark finally smelled the treasured dime. Having torn off the neck, the coin rushes towards the monster and gets stuck in its mouth, Scrooge without hesitation rushes after it. Magica calls Tiffany to her, and Ponka, thinking that her friend is in danger, distracts the monster from Lina and becomes the next victim of a shark. A little later, Lina also falls into the jaws of the monster, the girl is on the ledge and she has to make a choice: save her friend or let Magika pick up the dime. Lina chooses friendship, thanks to which she saves Ponchka and everyone else. The shark crumbles, and Roxanne Featherly arrives at the scene, putting Scrooge in an awkward position in front of the camera. As a result, he had to put up with the loss of his part of the fortune, but he was returning his talisman coin to himself.
A little later, Magika reports to Lina that she missed the opportunity by choosing her friend. But Lina has already begun to bore all this, the girl is about to leave, but it’s not so simple: Magika holds her back, declaring that she will get freedom only after she gets the Coin. Lina regrets lowers her Friendship Bracelet into the water. At this time, the awakened Donald was greatly surprised by the condition of his boat.