A man suspects his girlfriend of being unfaithful. So he sends her a letter, but than finds out that he was wrong. He has 24 hours to stop the package, prevent a disaster, and fall in love. The only problem is the delivery man will not stop until the package has been delivered.

For decades, next-door neighbors and former friends John and Max have feuded, trading insults and wicked pranks. When an attractive widow moves in nearby, their bad blood erupts into a high-stakes rivalry full of naughty jokes and adolescent hijinks. Will this love triangle destroy the two old grumps? Or will the geriatric odd couple overcome their differences and rediscover their friendship?