A raging volnado' (half volcano, half tornado) capsizes the Beavers dam during a party. Everyone escapes but Dag and Truckee. Handcuffed together, the two antagonists must escape from the sinking upside down dam. Meanwhile, Norb and the rest of the gang party in the volnado shelter not missing Dag or Truckee at all.
When the dam accidentally falls on Norb's head he develops damnesia and forgets who he is. Trying to restore his memory, Dag shows him old home videos. Norb is so shocked by how badly he used to treat his brother that he resolves not to become himself again, but instead become the always nice brother named Troy.
Norb checks the paper and sees a pair of the Mark 5 Model X-Ray Glasses that he must have! So instead of taking money out of his rich bank account, he goes "halves" with Dag and takes all his money! Soon Norb gets the glasses. He puts them on and all he sees is human hand bones. The real X-Ray glasses are invisible, and Dag's wearing them.
Everyone, especially Norb, is relieved when Dag decides to mimic his comic book hero Muscular Beaver and go into disillusioned retirement. His retirement is short-lived when he discovers that all along Norb has secretly enjoyed dressing up as his nemesis Baron Bad Beaver. The boys must fight one more super battle to end all super battles.
Combining elements of various outdoor games, the boys pitch and chip their way through their Beaver-rigged indoor golf course with its Quick-sand traps, soiled greens, Yahoo-filled water hazards, and full-contact putting. The game, however, soon takes a back seat when the Beavers become obsessed with which one gets to drive the way-cool golf cart.
Norbert wants to complete his celebrity curling iron collection by winning the prized Bo Donaldson curling iron. To do this, Norb attempts to sell chocolate to help poor, helpless squirrels who are nutless. When Norb enlists Dag as his salesman, things get crazy when Dag tries to sell one candy bar for $200, while Norb eats himself into a chocolate frenzy.