The first time we meet taciturn Woody Grant (Dern), he's walking down the shoulder of a busy road in Billings, MT -- so determined to reach his unknown destination that he fails to acknowledge the kindly police officer who's struggling to get his attention. When Woody's dutiful son David (Forte) arrives at the local police station to pick him up shortly thereafter, we learn exactly why the old man was so singularly focused on his stride: Having recently received a sweepstakes letter stating that he has won one million dollars, Woody is determined to claim his prize in person at the company's head office in Nebraska. Although David discerns right away that the letter is little more than a scam to sell magazine subscriptions, stubborn Woody already has tunnel vision -- nothing will stop him from obtaining his jackpot, even if he has to walk 800 miles on his own two feet to do so. Of course, this doesn't sit well with Woody's outspoken wife Kate (June Squibb) or career-driven son Ross (Bob Odenkirk), but David is determined to humor his befuddled father nonetheless, eventually agreeing to drive him to the sweepstakes office personally despite having to call in sick to work to get the time off. Shortly after the two set out, however, the road trip threatens to get sidetracked when longtime alcoholic Woody winds up in the hospital following a drunken fall. Pushing their schedule back to make time for his recovery, the pair plan to take a detour to David's Aunt Peg's house in his father's hometown of Hawthorne, where Kate and Ross will soon arrive for an impromptu family reunion. When Woody runs into his old pal Ed Pegram (Stacy Keach) at a local tavern and shoots his mouth off about his recent "windfall," he becomes something of a local celebrity, and familiar faces come out of the woodwork to claim their fair share of the prize. Meanwhile, David learns more about his family during this one eventful weekend than he did during his entire childhood, prompting some deeply personal reflection that offers him a whole new perspective on the father who was always something of a mystery..