Dagget becomes Muscular Beaver yet again, and this time he's in the clutches of "Toe-Bot". Norb's planning a big party, but he reluctantly becomes Baron "Once-Bad-Then-Good-Then-Bad-Again-Now-Good-Again" Beaver in order to "save" Musuclar Beaver. Fortunately for Norbert, when his guests (Treeflower, Barry, Bing, Truckie, and Stump) show up, they think it's a superhero-themed costume party, and become "The Justice Guys (And One Gal)" in order to help fight Toe-Bot.

The Beavers become characters in a Mexican wrestling film, starring their wrestling hero, El Grapadura, presented in Spanish (with respected English sub-titles).

The boys take a voyage to the bottom of the pond in their own Beaver-rigged submarine, the Norbalus.

Norb decides to embrace his European roots and becomes a brooding, world-weary Euro beaver. Industrious American beaver that he is, Dag struggles against Norb's laziness until Norb challenges him to see who can out-Euro the other.

Norb tries to rescue Dag who is held captive in the dam by three singing river rats.

When the Beavers win a trip to Branson, MO, they get their little sisters to come over and check on the dam. But their video taped instructions develops a severe glitch, and the little girls wind up doing all sorts of crazy things to the dam thinking it's what their brothers want.

In yet another scientific misadventure, Scientist #1 and Pete enlarge Dag to an enormous size so they can drive their plush custom van around inside him and learn the secrets of the pointy weasel thingys. It's up to Norb to stop them and return his brother to normal.