Driving through the desert en route to San Francisco, Sebastian has a chance encounter with Helena, a mysterious and attractive hitchhiker. Together they embark on a journey to the unknown, testing the boundaries of reality along the way.

Marion and Mingus both come from failed relationships but, by bringing their children together, they've managed to form a small yet happy family. Tensions in their household soon begin to spike when Marion's jovial father shows up on their doorstep with his randy daughter and her peculiar boyfriend in tow. As the motor-mouthed houseguests shatter every taboo imaginable, the happy couple begin to question their commitment.

Marion and Jack try to rekindle their relationship with a visit to Paris, home of Marion's parents — and several of her ex-boyfriends.