Jack (Freddie Prinze, Jr.) is a thirty-something NYC advertising exec, living a life forged from routine. He is successful and stylish... and entirely bored. Then, he meets Jill (Taryn Manning).
Twenty-one, fiery, adorable, and possessed of nothing resembling a routine, Jill enters Jack's life like a hurricane. They meet by chance on a rooftop, and move in together by week's end. Together, they piece togetner a playful manifesto of "rules to live by." Jack's best friend and partner, George (Peter Stebbings), notices a more playful side to Jack's usual cynical personality, and wants to meet the cause.
But there are storm clouds, as Jill's free-spirited nature causes some friction. When her long absences go unexplained, Jack forces Jill to confess that her disappearances are a result of the treatment she needs for Cystic Fibrosis, an ultimately terminal disease. Jack is furious with Jill for violating their pact of honesty, and they break up.
It is a talk with his father Norman (Robert Forster) that incities Jack to find Jill. Jack tracks down her wacky frien, Lucy (Vanessa Parise), and pleads his case. Convinced that he truly loves Jill, Lucy admits that Jill is catching a Greyhound bus cross-country to Los Angeles. Jack reevaluates his life, and just as he quits his job, a bomb threat is called in at his work. Jack goes outside and is surprised to find the culprit is Jill. The two make up, and with their new dog in tow, they hit the highway...with no destination in sight except for a life together.