The reason Santa's workshop has never been seen by polar explorers is because it's located under the North Pole. Once a year, Santa opens the passageway to the surface, but this year MAD is waiting and takes over the workshop to begin manufacture of a MAD Agent kit designed to hypnotize all the kids in the world and turn them into junior MAD agents. On Christmas Eve, someone sends a report to WOMP but Colonel Nozzaire thinks it's a joke; however, Gadget still believes in Santa and heads for the North Pole stopping enroute at the Last Resort, the only hotel that far into the Arctic. Penny has stowed away in the Gadgetmobile and learns from Santa's undercover reindeer George that the resort is under MAD control just like Santa's Workshop and the MAD agents running it intend to dispose of her uncle before he makes it to the North Pole. Can Gadget save Santa and Xmas before it's too late?

Dr Claw wants to get his hands on the sealed "Peace Arsenal" of the world's deadliest weapons and the key to it is in the possession of the daughter of WOMP's commanding officer. The same woman Gadget has just fallen for.

Two alien teenagers (technically one alien with two heads but the heads act like brothers) crash land in the desert while looking for a beach. Their arrival is detected by a hawkish General (Earth for Earthlings only!) who dispatches two crazed astronomers to gun down the aliens. Meanwhile, Penny is enjoying a weekend at the beach and Colonel Nozzaire dispatches Gadget to investigate reports of a UFO in the desert. Gadget picks up the hitchhiking aliens, but doesn't realize anything's unusual about them and takes them to the beach with the astronomers in hot pursuit.

After being thawed out of some ice he was trapped in, Dr. Thaw pays his 'bro', Dr. Claw a visit. They begin to argue about who can eliminate Gadget the quickest.

At the Young Inventors Expo, Penny unveils her latest invention (the Gadgetinis were her entry the previous year) a DNA tracker which can find anyone. Her friend Shawn shows off his invention an invisibility spray and is abducted by MAD Agents since Dr. Claw thinks the sprayer could be useful. While Gadget and the Gadgetinis are stumbling around, Penny finds Shawn but gets herself trapped in the MAD lab. So, the two young geniuses have work together to escape.

Marcus I, the King of Oblivia intends to put his obscure country on the map by relocating the Great Wall of China to Oblivia. Meanwhile, Gadget thinks a group of Shaolin Monks are responsible for its disappearance and tries to challenge them to a Kung-Fu showdown.

Colonel Nozzaire's idol, the famous TV Cook "The Silver Chef", is to prepare a meal for the president, but Gadget gets the assignment to make sure MAD doesn't poison the food the chef prepares. Unfortunately, the Silver Chef is a MAD agent and intends to get rid of Gadget and poison the president.

The tiny Himalayian country of Goldmanchu's only export is the gold created by the midas touch of the simpleminded mystic Golda (whose right hand turns things to gold and left hand turns things to wood). Golda's existence was a closely guarded secret but WOMP fears Dr Claw has learned of him and intends to use his golden touch to destabilize the world's economy so Gadget is sent to Goldmanchu. Unfortunately, Golda has already been replaced by an imposter with orders to eliminate Gadget.

A microscopic implant has been detected in the brain of General Gastritas. It's suspected to be a MAD mind control device and since he's about to be made Supreme Commander of the Mega Powers militaries, WOMP can't afford to take chances. So a volunteer is needed to be miniaturized by an experimental process and injected into the General's Brain to remove the device. It's a one in a millon chance of surviving the mission so Colonel Nozzaire is happy to volunteer Gadget. Gadget, the Gadgetinis and the Gadgetmobile are shrunk and injected into the General's skull to face angry white blood cells who don't like intruders and miniaturized MAD agents ready to defend the mind controller. Just to complicate things further, the scientists made a miscalculation when they shrank them and they have only a few hours rather than days before they return to normal size.

Colonel Nozzaire is a budding archeologist and author who has just written a book about the Aztecs. Too bad nobody's coming to his book launch except Gadget with news from General Sir. A recent earthquake in Mexico unearthed the entrance to the lost underground Aztec City of Gold. Rumor has it the Aztecs hid their "Crown of Invincibility" in the city and it's a prime target for MAD so WOMP has to find it before Dr. Claw uses it to become unstoppable. Colonel Nozzaire, Gadget, the Gadgetinis and an Archeologist descend into the city while Penny's left back at the base camp. She overhears assistant archeologist Ron Limond talking to Dr. Claw about how he found and hid the map to the secret entrance & shortcut tunnel that avoids all the traps. He heads off to the City and Penny breaks into his safe to find the map but Ron returns to pick up the crowbar he forgot and catches her. Ron forces Penny into the secret entrance tunnel and beats Gadget to the underground city's treasure vault.

The Colonel is taking his first vacation in twenty years, so it's Gadget mission to protect him from any MAD agents and let him have a good time.

Master of Disguise "The Chameleon" vowed to break out of jail for revenge on Colonel Nozzaire and, thanks to some inadvertant aid from Gadget, he's now free to seek vengeance.

CIA Agent Foxy discovers a MAD plot to use a mysterious metal from a meteor to turn people into animals just before he's turned into a fox by a MAD scientist. Foxy is teamed with Gadget to crack the case but Gadget thinks he's the Colonel's talking pet dog.

Dr. Claw seems to have reformed and has become the new CEO of the humanitarian organization GloboCare. Gadget believes he's changed but Colonel Nozzaire (and Penny) suspects he's secretly plotting something and sends Gadget to GloboCare to investigate undercover.

Gadget is sent to Paris to protect the world's most famous (and only) canine artist "Roverre". Meanwhile, Dr. Claw intends to abduct the dog and make him teach Mad Cat how to paint so he'll be the world's only animal artist and people will pay millions for his paintings.

The 10 biggest banks in New York have been robbed but despite the break-ins happening in broad daylight there are no eye witnesses, the security cameras shut down and no one can remember what happened. The only clue is that everyone who was in the banks remembers hearing bagpipe music before the robbery. The police have no clue so WOMP is called in and Gadget is sent to Scotland accompanied by Penny & the Gadgetinis to investigate the only clue - a security camera closeup of the name McIntosh's Magic Bagpipes Inc. on the pipers bagpipes.

Dr. Claw hires two corporate headhunters to find him the ideal second-in-command and they use Halloween as cover to invite candidate criminals to a Halloween party in a trap filled house so they can be tested. Guess who stumbles into the party while trick-or-treating with Penny.

Gadget is guarding some military vehicles that were leant to a new movie being filmed. What he doesn't know is that the entire crew (except for the mfamous star) are all MAD agents, there to steal the vehicles.

WOMP intercepts a MAD transmission and learns that they have located the supposedly mythical island of Shangrilala. The waters of Shangrilala are a real fountain of youth and Dr. Claw intends to use them to make himself and his agents immortal and sell the water to dicatators who'll do his bidding for eternal youth. Gadget is sent to the island to protect it but by the time he arrives MAD has already imprisoned all the islanders, renamed it Claw Island and begun draining the waters. As always Gadget hasn't a clue anything's wrong so it's up to Penny and the Gadgetinis to make Gadget save the day again.

A crazy opera singer who can control bees with her voice and turn regular bees into "killer" bees uses them to rob Fort Knox then sets her sights on making Washington, DC her personal beehive. Can Lieutenant Gadget stop her? Maybe, if he ever figures out that his favorite opera singer is up to no good.

Gadget, Penny & the Gadgetinis travel to the small western town of "Cut N' Shoot" for the ceremony to rename the town as "Gadgetville". But, when they arrive the town seems deserted because everyone's hiding. The fearsome Barker Gang is on the way and since the sheriff can't handle them they're renaming the town so Gadget will. Too bad he thinks it's all a game.

WOMP is broke so Gadget is entered into a TV survival show with a $10,000,000 grand prize. The problem is the other contestants on the island (the superstrong Mountain Momma, the slime monster Swamp Man and the feral Rat Boy) were specially recruited by MAD to destroy Gadget during the show's extreme stunts and make it look like an accident.

Gadget is sent to investigate why Dr. Claw is holding a contest with a $1,000,000 prize for the owner of the world's stinkiest animal. Meanwhile, Penny has given the Gadgetinis an experimental digestive systems so they can eat and turn food into electricity. They quickly become addicted to eating and try everything which causes the digestive systems to overload and emit noxious odors so they win the contest. Gadget is happy to get the check but the contest is a front for a MAD plot. The winning animal is to be squished and their concentrated stink extract used to arm an orbiting stink bomb which will cover the world with a foul-smelling stench. Then, MAD will sell the scent neutralizer their chemists created for a fortune since everyone in the world will be a customer. Since the Gadgetinis won, they're taken to the squashing machine and Gadget's too happy to have won $1,000,000 to interfere so it's up to Penny to save the day.

A MAD agent equipped with a mask of Gadget's face and retina prints, plus his fingerprints and scent, enters WOMP and takes the Gadgetmobile and uses it for a crime spree. Using its vacuum attachment, he's able to clean out diamond exchanges and armored cars filled with gold. Gadget is arrested and taken to prison but believes he's won WOMP's Agent of the Year award and has been sent to a vacation resort. While Colonel Nozzaire is initially happy to be rid of Gadget, that changes when General Sir tells him that without their only field agent the Board of MegaPowers will shut down WOMP. Meanwhile, Penny and the Gadgetinis are trying to find the imposter before the other prisoners get rid of Gadget and WOMP ceases to exist.

Gadget is sent to Switzerland to protect a fleet of "subatomic" (?) atomic sumbarines concealed in Lake Geneva while they await decommissioning. Unfortunately MAD agents have already infiltrated the subs crews.