The sleepy Pacific Northwest town of Eureka is hiding a mysterious secret. The government has been relocating the world's geniuses and their families to this rustic town for years where innovation and chaos have lived hand in hand. U.S. Marshal Jack Carter stumbles upon this odd town after wrecking his car and becoming stranded there. When the denizens of the town unleash an unknown scientific creation, Carter jumps in to try to restore order and consequently learns of one of the country's best kept secrets.

A game warden moves his family to Lake Placid, once the site of deadly crocodile attacks. Locals assure him the crocs are gone, but his mischievous young son finds a few baby crocs and begins feeding them. They quickly grow into very big adults and start attacking the game warden's family and nearby town.

In an effort to prevent family history from repeating itself, meddlesome mom Daphne Wilder attempts to set up her youngest daughter, Milly, with Mr. Right. Meanwhile, her other daughters try to keep their mom's good intentions under control.