Een gigantische meteoriet zal over 18 dagen inslaan op aarde. NASA roept de hulp in van Harry Stamper, een boor-expert, om de astronauten te trainen. Harry denkt echter dat de astronauten niet op tijd getraind kunnen zijn, en besluit zelf met z'n crew de klus te gaan klaren.
Three young boys, Rocky, Colt and Tum Tum together with their neighbor girl, computer whiz Amanda are visiting Mega Mountain amusement park when it is invaded by an army of ninjas led by evil Medusa, who wants to take over the park and hold the owners for ransom. Kids and retired TV star Dave Dragon, who made his farewell appearance at the park at the time the ninjas appeared, have to break Medusa's vicious plans.
When an experienced thief accidentally makes off with a Van Gogh, his partner is kidnapped by gangsters in pursuit of the painting, forcing the criminal to hatch a rescue plan.
A prize-fighting boxer with a lethal right punch falls for a gangster's moll on the run in Mexico.