Gyro Gearloose wants to show Donald his new invention, called the "shotgun". Donald laughs at him as everybody knows what a shotgun is, but then Gyro paralizes him, puts a robotic frog in his pocket, and unparalyzes him a few minutes later, with the frog as a proof that Donald was paralyzed. Then Gyro explains his invention is a paralyzing shotgun, and gives it to Donald as it may be useful.
Donald intends to use the shotgun to play a prank on Scrooge McDuck who is picking ols newspapers to read at the park. However, Donald arrives just in time to see Scrooge being kidnapped. He follows the kidnappers who use a spray to sleep Scrooge as they were ordered not to harm him. At their hideout, the kidnappers call their boss who orders them to keep him there until tomorrow at noon. They go to buy some food and the Duck Avenger takes the chance to sneak into the hideout.
When the kidnappers return, a hidden Duck Avenger disintegrates their wine bottle, so each believes the other took it and they fight until the Avenger leaves his hiding place and they confess they have never seen their boss, only know their number and Scrooge will be free when they get paid. Then the Duck Avenger uses the shotgun to freeze them, frees Scrooge and awakens him.
Scrooge deduces the one who wanted him away til noon is John D. Rockerduck, because if Scrooge doesn't go to the court at 11:00 to get a land, it will be Rockerduck's. The Avenger wants to drive Scrooge home, but as he could recognise the 313, he hsa Scrooge driving the kidnappers' car. This ends bad as some cops stop the car due to its covered license plate, and then they find criminal gimmicks in the car, so Scrooge is arrested.
The Duck Avenger becomes Donald again and goes with Gyro to confirm the shotgun's effects will wear off even if he doesn't unparalyze the victim, so he doesn't need to return with the paralyzed kidnappers. Back at Donald's House, Huey, Dewey, and Louie tell him that Uncle Scrooge was arrested. Patiently, Donald eats dinner and sleeps to get an idea, until he finally has a plan. He sends the kids to see Scrooge, while he calls the police as the Duck Avenger and tells the true facts.
At 11:00, Rockerduck goes to the court promising to eat ten hats if he doesn't get the land. The Duck Avenger, disguised as Rockerduck, goes to his house and awaits his return. When Rockerduck returns, the Duck Avenger gets the property deed of the land and makes Rockerduck write and sign a declaration. After leaving, the Avenger turns into Donald and calls the police to get the two kidnappers.
Donald goes to Scrooge with the papers the Duck Avenger "gave" to him. The declaration says Rockerduck gives Scrooge all the property rights of the land if he gives a thousand dollars to Donald. While Scrooge spends the day at the swampy land, Rockerduck eats his ten hats, and the kidnappers fight each other in their cell, Donald and his nephews spend vacations in a tropical paradise.