Pittsburgh, Pennsylvania, 1991. High school freshman Charlie is a wallflower, always watching life from the sidelines, until two senior students, Sam and her stepbrother Patrick, become his mentors, helping him discover the joys of friendship, music and love.

Six years have elapsed since Guantanamo Bay, leaving Harold and Kumar estranged from one another with very different families, friends and lives. But when Kumar arrives on Harold's doorstep during the holiday season with a mysterious package in hand, he inadvertently burns down Harold's father-in-law's beloved Christmas tree. To fix the problem, Harold and Kumar embark on a mission through New York City to find the perfect Christmas tree, once again stumbling into trouble at every single turn.