Arthur's Mountain Adventure

Arthur's Mountain Adventure is a 2009 American made-for-television animated comedy-drama fantasy film based on the PBA series Arthur, itself based on a children's book series of the same name by Marc Brown. It was directed by Alex Zamm and produced by 9 Story Media Group. The film focuses on the Read family taking a vacation to the Yukon.

Plot
Jane and David Read and their children Arthur, DW, and Kate are preparing for a summer family vacation to the Yukon in Canada. After DW catches him disobeying his parents to try and sneak out to a PG-13 movie, Arthur is forced to go on the trip as well. There, the family learns about the history of the Yukon and how important it is to preserve our natural resources. Arthur is given a magic coin that allows the user to make one wish by a tour guide during their trip.

Later, Arthur is caught bullying DW, which results in his father grounding him for the rest of the summer. In a fit of rage, Arthur wishes that he didn't have a sister and that his parents had never met. The magic coin he had in his hand grants his wish and as a result his family do not remember each other or him.

Arthur and his friend Buster (who is later found to have visited the Yukon as well) attempt to get the coin from the tour guide, but he catches them; he is shown to be a wizard, as he has not had to give them up. The guide asks him what would happen if a kid wished that their family never met; He explains they would gradually forget their past before disappearing forever. He says it would take a miracle to fix it, leading guide to mention the Stone of Dreams, which he says would work too.

Eventually, Arthur and Buster succeed in finding the Stone of Dreams. He tells David, Jane, and DW his story. Jane doesn't believe him, believing she would not forget her children. Buster mentions that if they were wizards like their tour guide was, they might be able to cast a spell to reverse it. Max finally loses all of his memories and is sucked into a vortex of non-existence. Theresa remembers him, realizing that they were telling the truth. Jerry transports Alex and Justin to an ancient battlefield and explains the contest's rules: They will only be allowed to use spells involving the four elements (water, earth, fire, and air), and the winner will become a full wizard, while the loser will permanently lose their powers. Alex and Justin engage in what turns out to be an intense battle, with Alex narrowly winning it.

In a state of worry, they turn to DW for help. However, by now DW has lost all her memory; Arthur tells her that even though they pick on each other, he looks up to her and begs DW not leave her here alone. DW tells him that she'd never leave him and that even though she doesn't know him, she believes him and wants to help, but he is quickly sucked into the vortex.

Arthur wishes that everything would go back to the way it was. Time rewinds to just before Arthur makes the wish that his family did not exist, where he apologizes for her attitude and accepts her punishments with grace. After lovingly meeting up with his sisters again, the family happily strolls along the mountain resort once more.