King

Cliff gets Russel to go to Under and recover his memory of Grade 4, which he forgot after falling into the GeeIForget River on the same day he had hidden the second Crown of Under. Bob was also looking for the second Crown, and decides to get Cliff’s memory so he could find the Crown and get 50% control over Under. Unable to steal it from the Recollecter at the river's end, Bob then decides to get Russel to get the memory instead then he’d steal it from him. But he remembered that he had set traps all along the river bank to stop Russel, and one of them knocks Russel into the river, making him forget everything.

When a giant Asymptote appears but stops short of the town, the Underites start panicking, and Vernon goes dangerously Babbleyboing. In order to stop him from exploding, Russel takes him to the Clockmaker, who now lives in the Bottomless Pit. Unfortunately, the Clockmaker gave all his belongings to his love Flavia, and as such will be unable to fix Vernon until he marries her. Meanwhile, Loopy and Gus try to get rid of the Asymptote, with Bob (who is making a killing in the therapeutic business) fouling them up at every turn.

As an alien fleet approaches Under, Russel is arrested by Agent Greg and his Future Infractions Bureau for a crime he has yet to commit. The others head to the Museum of Tomorrow to try to find out what crime he will commit, but are arrested themselves for planning on breaking Russel out of jail. Gus has everyone speak in past tense instead of future tense so they won’t be caught again, and he and Russel escape with the help of Vernon, Loopy and Populah, and head to the Museum to visit the future.

When Russel overhears that his mother needs money and is going to sell the house, he goes to Under to find some treasure for her instead. He and his friends head out to collect the Orb of the Zinkas, an extinct sugar-loving culture. Bob tries to stop Russel, believing if Under got a new King, he’d stand a better chance of stealing the Crown.

During the live production of Bob’s new TV talk show, Auntie’s prized Charismango Tree disappears and she wrongly accuses her new Thorch of eating it. Russell decides to save the Thorch and bring it back to its forest home, but Auntie hires the famous tracker Mr. Queep to get it back. Meanwhile, Vernon and Loopy try to find the real culprit, with Bob, the Frags, Hugh the Yu-Yu and Cousin Tess as their main suspects.

Loopy "trespasses" in Near Under while picking flowers, causing Auntie to declare war. Russel calls for a truce but when they meet at the peace talk, Bob has them eaten by a Gurd, which turns them into eggs. When Russel hatches he becomes obsessed with getting to the top of Unclimbabale Mountain, but the Troll who owns it tries to stop him. When Auntie hatches she becomes infatuated with Loopy and puts him in a cage, he then asks her to get the Crown for him, since he saw that Bob had stolen it from the preoccupied Russel.

The Frags are forced to join Loopy as Gopher scouts for their community service hours and together they steal the last Thussle bush, which had been causing a war (both the Red and Yellow Floronians wanted it). They give it to Bob Wire to keep safe, and he tells the Floronians that Russell has it causing them to attack Under. Bob tells Russell he will give it back and end the siege if he gets the crown, however Captain Darling decides to use the Thussle as a Despot Day gift to Auntie First.

Scared of a storm, Gus has Russell go down to Under where the Horrorborealis is filling the skies, turning everyone organic (i.e. not Vernon and Bob) into pickle-obsessed Ghouls. Russell, Gus and Bob gets hit by lightning and are negatively charged, protecting them from everything even turning into Ghouls. Russell decided to go to the West Pole where his charge will be neutralized, and end the Horrorborelais as well, allowing everyone to return to normal. Bob, however, gets himself positively charged and threatens to neutralize Russell himself unless he gets the crown, but Gus ends up turning into a Ghoul. Meanwhile back in Under, Vernon has to eat all the pickles so the Ghouls can't themselves, as that would make them remain in their monstrous state forever.

Bob kidnaps Gus and Loopy, sending them floating away to Dessert Island where they are beset by ravenous Sea Scarfs. He then has a Shapeshifter turn into Gus to steal the Crown, but the plan is disrupted when Russel and the Shapeshifter have to save Vernon from a nest of baby Geets.

The Kingdom inspector is making his rounds and Vernon, Populah and Loopy are cleaning up Under in preparation, kicking everyone out. If the kingdom’s dirty, then Russel will lose his crown, so Bob sets out to turn the town into a dump. Unknowingly Auntie First uses an obscure legal loophole to swap ownerships of hers and Russel’s kingdoms, leaving Vernon and Loopy to clean up filthy Near Under in a few mere hours. Meanwhile, Russel, Gus and Populah have to get the last stamp required in Under’s Stamp Collection from Elpsun C's post office (without which he will lose his crown also).

Auntie gets a Spitesucker stuck to her face when she visits Bob’s Aqua Zoo, forcing Captain Darling to make a deal with Cousin Tess to get it off. Unfortunately once she was freed, Auntie couldn't remember being sucked and was forced to try Darling and Tess for treason. Meanwhile, Russel also visits Bob’s Zoo and gets attacked by a Plurn. Gus saves Russel but the Plurn inks him, turning him into an aquatic animal. Russel goes to ask Tess how he can get Gus back to normal (leaving the finned dog with Bob and Loopy, who put him on show), but Tess refuses to help Russel until he wins her and Darling’s trial.

Loopy accidentally activates the jetpack Vernon was making Russel and rockets away to a distant village of Iples who dub him their "Great Decider" (they can't make decisions themselves). Meanwhile, Populah’s hair has been turned into snakes by Auntie’s shampoo, and Auntie won't share the antidote unless Russel gets her a date with Mr. Queep. Queep agrees to go on the date once he has captured a Nonifer up in the monster-infested NotVeryKnown River, but his canoe sinks at port. Gus volunteers Russel’s King Ship and they accompany Mr. Queep on his quest, along with Bob and the Frags, looking for a story to sell their tabloid, the Hotwire

Bob Wire releases Gag Pune from Mount Stoney Lonesome, he was imprisoned in when Cliff was King. Gag was imprisoned in the mountain after going on a rampage after being laughed at by Cliff, Bob and the inhabitants of Under during a festival. Bob freed Gag because he knows the first thing he'll do is head to Under to destroy the place and Russel will have no choice but to get Cliff's help, and the price will be the Crown of Under. Meanwhile, Loopy needs to get his nose bell fixed and we learn that he's more than just the court jester.