Linus and Lucy's baby brother, Rerun, believes he'll be the happiest little boy in the world if he receives one very special Christmas gift - his own dog. Unfortunately, his mom won't get him one, and he doesn't have the ten million dollars Charlie Brown says it will cost to buy Snoopy. Rerun figures there must be a way, and when he learns that Snoopy's brother, Spike, is coming to visit, he decides that he'll adopt him.

Charlie Brown decides to send Snoopy back to his puppy farm for obedience training, but Snoopy is less than enthusiastic. He goes as far as Peppermint Patty's place, who agrees to let him stay for the night. He overstays his welcome as a freeloader and Charlie Brown drags him back home.