When Homer joins the Naval Reserve, a captain takes a liking to him and leaves him in charge of a nuclear submarine.

After spraining his knee during a basketball game, Homer begins taking care of the neighborhood kids to cure his boredom, prompting jealousy from Bart and Lisa, who feel that Homer is giving the kids the attention they never had.

Lisa travels back in time to 1923 and discovers that the Springfield Mini Moose, once key to the town’s ecosystem, were driven to extinction in 1925. Teaming up with young Monty Burns, Lisa works to save the moose, but her actions unintentionally shape his future as a ruthless tycoon.