The Duck Avenger saves a woman from a little mouse, but she tells the newspapers it was a huge beast, so the Duck Avenger's fame skyrockets. However, he is soon overshadowed by a rock band and everybody goes to their concerts (save Donald and Huey, Dewey, and Louie, whom Donald orders to hear stories about the Duck Avenger). When the people returning from the concert find their things have been stolen, they blame the Duck Avenger for not protecting them out of envy to the band.
That night, the Duck Avenger patrols the city while the Duckburgians are in another concert, but to no avail as things are stolen again anyways. He deduces the robberies began at the same time that the concerts, so he goes incognito to a concert wearing fedora, trenchcoat and shades. the Avenger finds the lights of the concert hypnotize the Duckburgians, and the band actually are Grandpa Beagle and the Beagle Boys, and Grandpa orders the people to leave the things they stole to themselves. A Beagle notices the guy in the trenchcoat isn't hypnotized, so he reveals his Duck Avenger costume, but must flee as he cannot fight with so many inoccent citizens in the way.
While fleeing, the Duck Avenger accidentally finds the actual rock band members, tied by the Beagle Boys, so he frees them and has them play so their music de-hypnotizes the Duckburgians, who beat the Beagles.
In honor of the Duck Avenger, the rock band changes its name to The Duck Avengers and play a concert in his honor. Donald, Daisy and the kids attend, and Daisy wonders why the Duck Avenger didn't come, to which Donald replies he will tell the Avenger how did the concert go.