The two scientists mistake Dag for a long extinct horned beaver and Norb tries to rescue his brother.
Dag and Norb are at a construction site. Dag says he could operate bulldozers easily. Norb allows him to try it. Dag attempts it, but ends up setting the area on fire and giving himself a huge bump on the head. They manage to get to their dam before the explosion. Dag starts yelling at things, including a burnt up portable toilet. It falls apart revealing the two scientists. Norb recognizes them, but Dag does not.
Scientist #1 claims that he and Pete are environmentalists now (because they have green coats). He also says they're here to protect a rare species, the last of the great horned beavers. Dag wonders where he is, and it turns out he is the rare beaver. Scientist #1 also thinks that he and Pete could get a Nobel Prize for this. He also states that Dag has the biggest beaver horn he has ever seen, which Dag thanks him.
Norb interrupts, saying that Dag is just an ordinary beaver who brained himself operating heavy equipment and also Norb is taking him home. Scientist #1 says Norb can't do that because Dag is now under government protection now and has Pete zap him with a weird weapon. Norb storms into the dam all zapped while Dag is being studied. Dag makes fun of Norb for getting zapped. Norb tells him to stop and to get the scientist geeks out of their dam.
Dag instead claims that he is being threatened by Norb, which results in Norb being zapped again. Outside, Norb reads a sign claiming that their dam is the "Great Horned Beaver Nature Preserve". Dag enjoys it and runs inside. He taunts Norb again, which causes Norb to get angry again. Dag says he's being threatened and Norb gets zapped by two giant zap rays that come out of the ground. Dag is inside claiming he loves being endangered. He accidentally hurts his finger and Scientist #1 gets overprotective. He claims the last of the horned beavers is too important to take chances.
Scientist #1 and Pete give Dag a special suit and keep him under watch. Dag sneaks outside and finds Norb. He asks if he is still mad at him. Norb says he is not mad, but livid. Dag also thinks Norb isn't going to help him cause his endangerment is backfiring, and Norb says no. An alarm goes off and the scientists snatch Dag up and take him away, but not before zapping Norb one more time. Norb is watching the T.V. when a program on Dag comes up. The scientists think they may be able to find more horned beavers, while Dag writes something on the side of his container.
Norb starts to miss Dag a little and reads what he wrote ("I miss you Norb. Please 4-give me"). Norb states that Dag might be a half wit, but he's his half wit and proceeds to try and save him. Norb sneaks in and covers himself with a pillow. He finds Dag, but ends up getting zapped again. A package arrives from a "friend". Scientist #1 decides to investigate. He opens up find a weird machine. He says it is the new horn swoggler for horned animals. The scientists try to find out how it works. Turns out that Norb hid in the foam and tries to free Dag again.
Another package comes for "the pointy weasel sneaking around in the packing foam". Norb opens it and gets zapped again. Norb makes it outside. He says if he keeps trying to help Dag, he'll end up an endangered species as well. This gives Norb an idea. Someone knocks on the door and the scientists are prepared to defend. They open the door and see a weird creature. Norb introduces himself as the last of the "Great Many Horned Beavers" (with a branch and bike horn as fake horns).
Scientist #1 claims that because Norb has many horns he is more important. He takes Dag's suit off and accidentally blows Norb's cover. They prepare to zap him again, but Dag asks them to stop. #1 claims that Norb was write about Dag all along. He says if he and Pete were ordinary people they would apologize, but being scientists they don't need to. They plan on leaving, but Norb makes it so that when they leave it goes horrible. Dag is glad that it's all over, but Norb says it isn't. He has his own zap ray and uses it on Dag repeatedly, as revenge for him getting zapped all the time.
- Running gag: Norb getting zapped and every one putting emphasis on the e in horned.
- Touch Me - The instrumental version of the 1968 song by the Doors was briefly used as background music at the beginning of the episode.
- Richard Horvitz as Daggett
- Nick Bakay as Norbert
- Ed Winter as Scientist #1
- Gregg Berger as Bill Licking