Inspector Gadget is a clumsy, dim-witted human cyborg detective with various bionic gadgets built into his body. Gadget stumbles around working the cases while his niece and dog do most of the investigating. Gadget's arch-nemesis is Dr. Claw, the leader of an evil organisation, known as "M.A.D."
The Great Wambini, famed magician and M.A.D. agent, gives a performance Metro City will never forget -- with the demise of Inspector Gadget as the planned finale.
All the pets in Metro City are being kidnapped, and M.A.D. is the likely suspect. Could the Great Wambini be the key to the case?
The Great Wambini goes to Alpakistan to win the King's diamond-spitting llama by making three accurate predictions. Gadget is sent along to investigate M.A.D. involvement, and ends up playing in the National Floobyball Tournament.
Corporal Capeman joins Inspector Gadget posing as his assistant while Gadget pursues the notorious ninja.
While Gadget trains his new assistant Capeman, Dr. Claw launches a crime spree to celebrate M.A.D.'s anniversary.
Inspector Gadget and Capeman are both sent to a clinic run by M.A.D. They tell Gadget that they are going to test his gadgets, but in reality they plan to destroy them.
Professor Dumkopf of M.A.D. unleashes the Linguinis, five little imp-like creatures, on Inspector Gadget's house with the mission of deep-sixing the Inspector.
Professor Dumkopf of M.A.D. is back, this time with a shrink-ray gun he uses repeatedly on Inspector Gadget in an attempt to shrink him into nothingness.
The Gadget clan faces one last threat from M.A.D.'s Dr. Dumbkopf, which involves battling his hulking, irascible humanoid assistant named the Grappler. Fortunately, sweets, candies, and ultimately Penny's kindness help in soothing the soul of this misunderstood beast and thwarting Dr. Dumbkopf for the last time.
Dr. Spectrum of M.A.D. invents "Ghost Globules" -- pellets that produce glowing ghostly critters. He plans to sets them loose on Metro City, then offer to sell people a spray that will banish them. Inspector Gadget investigates a costume party while on the trail.
Under the guise of a local telephone company, M.A.D. inventor Dr. Spectrum and his goons systemically target the mansions of Metro City's elite neighborhoods and proceed to burglarize them with the dial of a number and with a zap of a teleportation gun to send the loot straight into Claw's hands.
Something ominous is inexplicably causing the citizens of Metro City to be beset by unstoppable nightmares.
When a space station orbiting Earth goes silent, Gadget must investigate. Penny and Brain tag along aboard the space shuttle that takes Gadget to his destination, where Penny discovers that the station's soft-spoken HAL-like supercomputer is under the control of two M.A.D. agents, Dr. Null and Dr. Void. Their evil plot involves a giant magnifying glass that can aim and intensify the sun's rays towards Earth.
Using bombs disguised as kewpie dolls, Dr. Claw and his agents, Null and Void, scheme to alter the surface of the moon so that it will resemble the M.A.D. logo.
M.A.D. gains control of Metro City's banks, by tapping into an orbiting satellite. With the added distraction of "Crazy Gas", a substance that induces hallucinations in their victims, can even Inspector Gadget ever hope to regain control of the city's bank accounts?
A M.A.D. agent devises a plot to bring dinosaurs back into the 20th Century so Dr. Claw can crush Metro City, while at the same time killing Gadget's ancestors to ensure he never exists in the present.
Inspector Gadget, Penny, and Brain travel back in time again -- on this occasion, to ancient Rome to prevent Dr. Claw's own time traveler, Thelma Bodkin, from deciphering an ancient mosaic and stealing the treasure it describes.
M.A.D. agents travel back in time to 19th-century England to steal the crown jewels and wipe out Inspector Gadget's ancestors, chimney sweeps named Chimney and Char Gadget. Gadget is assigned to follow them back in time and stop them.
Dr. Claw hires a retired mob boss, the wheelchair-bound Great Great Godfather, to assassinate Inspector Gadget.
Dr. Claw seeks the wise advice of his mentor in destroying Gadget and winds up with two Black Widows who believe assassinating Gadget would be their cup of tea.
Dr. Claw brings gangster Spuds Malone out of retirement to eliminate Gadget with his infamous potato-firing tommy gun "Red Rose".