Harold, a nerdy office worker, and Kumar, a stoner, embark on a journey to find a White Castle and end up having a series of hilarious and outrageous adventures along the way.

Harold and Kumar reunite for a wild Christmas adventure after accidentally burning down Harold's father-in-law's prized Christmas tree. Along the way, they encounter Santa Claus, robot maids, and various outrageous situations that test their friendship.

After being mistaken for terrorists and thrown into Guantánamo Bay, stoners Harold and Kumar escape and return to the U.S., where they proceed to flee across the country with federal agents in hot pursuit.