Inspector Gadget, Penny, and Brain are on vacation in the Caribbean. But before they've had a chance to get any serious r. & r. on Gadget's dilapidated old rust-bucket of a boat, duty calls and the Inspector's back to work. After sinking his own vessel, the police inspector, his niece and his dog are rescued by a passing cruise ship - the very ship that's gone missing! While a quartet of lovably stuffy billionaires coo and cluck over the exciting "fake rescue" and its castaways, the ship's MAD agent captain, Malcolm, learns from Dr. Claw that he's just saved the trouble-making Inspector Gadget and now must eliminate him. Gadget disappears below deck to fix the ship's engine when an 18th century pirate ship appears on the horizon. With MAD agent Pegleg Peg at her helm, the ship sails up and the wealthy passengers are captured. Threat after threat to the four good-natured bluebloods are laughed off as all part of "The Pirate Island Fun Tour," and they refuse to sign over their fortunes for fear of ending the adventure. It must be an act since the numerous attempts on the life of surprise guest celebrity Inspector Gadget keep failing - but savvy Penny and hard-working Brain know better! After landing on Skull Island (with the requisite skull formation in the rocks), Malcolm hits on an idea: Sign the papers, he tells the jovial group, and you're assured a spot on next year's tour. Before you can say "power of attorney" or even "fine print," they've all scrawled their John Hancocks on the forms. Now it's just a matter of getting those documents to Dr. Claw so he can take possession of their billions - but in swoops Brain who snatches them away from co-conspirators Peg and Malcolm. It's a mad dash to the end as each of the billionaires bags a MAD agent and Gadget yanks the papers from Brain's paw just as they both stumble across Chief Quimby, bringing an end to this adventure - but not before Inspector Gadget promises to take Penny on The Pirate Island Fun Tour next year!