While hiding from a woman looking to kiss him, Drake accidentally makes an unbreakable promise to a little girl named Mary Alice to give her family the best Christmas ever.

Gilbert sabotages the duo's attempts to give Mary Alice's family the best Christmas ever, so Drake bribes Megan with his friend Trevor's rare Royal Smith oboe passed down from his grandfather.

Still determined to keep their promise, Drake and Josh borrow Steve's woodchipper (“Sally”) to make it snow in front of Mary Alice's house by putting ice in the machine.

In trying to stop the machine, the brothers are knocked unconscious but are brought home by Gilbert, who was secretly gifted a nice chimpanzee by Josh and began to love Christmas again.

The brothers enter the living room the next morning, where Mary Alice's family surprises them, having learned the truth from Gilbert.

Bludge, dressed as Santa, comes down the chimney to deliver gifts to everyone, including a real Royal Smith oboe for Megan.

Walter and Audrey return home from their vacation, which turned out to be at a small dilapidated hut that blew away in a tropical storm.