Bart fills out an application for a credit card in Santa's Little Helper's name. The card is approved. Bart uses it to shop for catalogue items and buys a collie named Laddie from Vermont. The dog is well-trained and the family falls in love with him.

Bart fails to pay the balance on his credit card bill and the bank repossesses Laddie. When the repo men arrive, Bart gives them Santa's Little Helper instead. He immediately feels guilty. Tiring of Laddie, Bart wants Santa's Little Helper back.

Bart gives Laddie to the police and sets off to find Santa's Little Helper. His search ends at the house of a blind man named Mr. Mitchell. Bart tries to kidnap his dog, but Mitchell traps him in a closet and calls the police, who arrive shortly afterwords. Laddie seems to take an immediate liking to Mitchell, but is, in fact, sniffing out a bag of marijuana in his pocket. Bart leaves with Santa's Little Helper as other police arrive at Mitchell's house with beer and party to reggae music.