Mr. Burns announces a million-dollar prize for alternative energy inventions as part of a court settlement.

Professor Frink unveils a vehicle powered entirely by sound waves, which goes out of control.

Homer avoids helping Marge pack Grampa's belongings, claiming back pain.

Homer becomes obsessed with a medieval village building game on his tablet.

Marge returns home and discovers the family dog, Santa's Little Helper, is missing.

The family searches for Santa's Little Helper, eventually finding him locked in a kitchen cabinet.

Homer admits he is not a dog person, prompting Grampa to tell a story about Homer's childhood dog Bongo.

Grampa recounts Homer's happy childhood with his dog Bongo, set to a song.

Mr. Burns gives away toys at a PR event, and Bongo bites him, leading to a threat.

Grampa takes Bongo to a remote farm to hide him from Mr. Burns.

Young Homer realizes Bongo is gone forever and cries as Grampa drives away.

Grampa makes a deal with Mr. Burns to save Bongo, enduring humiliation.

Young Homer becomes angry with Grampa, and their relationship suffers for years.

Homer tells his own version of the story, then reveals he later visited Bongo.

Homer realizes Grampa saved Bongo and apologizes, leading to a hug.

Homer finally shows affection to Santa's Little Helper, putting him to bed.

Mr. Burns gives a confusing public service announcement about the fiscal cliff and immigration.

The episode ends with credits and subtitles.