After escaping jail, the Beagle Boys kidnap Donald and give him food to fatten him so they can ask Scrooge McDuck his weight in gold to release him. After a week of fattening Donald, Grandpa Beagle calls Scrooge who gets the visit of Huey, Dewey and Louie, who are worryed about Donald. Scrooge doesn't intend to pay the money, but accepts the kids' idea of asking the Duck Avenger's help on his TV channel.
The basketball game the Beagle Boys are watching is interrupted by Huey, Dewey and Louie's transmission. Grandpa Beagle gets afraid of the idea of the Duck Avenger intervening, so they release Donald taking him to a truck and kicking him out in a random place. Donald decides to later return as the Duck Avenger to give them a lesson.
Donald finds the 313 was taken by the police fro obstructing the transit, so he sneaks to get it back, dons the Duck Avenger costume and leaves. Then he goes to Scrooge's house at night and scolds him for not paying Donald's rescue, and Scrooge must sign a document allowing Donald and his nephews into his hotel for millonaires so the Duck Avenger doesn't disintegrate his gold.
The Duck Avenger seeks the Beagle Boys' hideout, that should be in a nearby island as they had a short boat trip. When he doesn't find any hideout, remembers he was fed with trouts, which can be found in the Witch Lake. When the Avenger finds the hideout, he cuts the electric power. Then he uses the 313-X's booster to hover over the lake and the headlights make the Beagles look it as a monster.
When the Duck Avenger arrives, he has Grandpa Beagle and the Beagle boys leave their hiding places and treathens Grandpa into calling the rest of the gang. When the other Beagle Boys arrive by truck, the Duck Avenger has them all locked in the trailer and has Grandpa Beagle drive to jail.
Later, Donald goes back home and tells his nephews that the Duck Avenger rescued him. He goes to sleep and the following morning Dewey tells him Scrooge has called to allow them into the hotel for millonaires. There, Donald says he needs rest after all the work he did, and Louie tells the Duck Avenger did all the work to rescue him.