The Old Man and the Lisa

"The Old Man and the Lisa" is the twenty-first episode of season 8.

Plot
Principal Skinner and Lisa are recycling to get enough money for a field trip, and during a reunion among the recycling group (the "Junior Achievers Club"), Mr. Burns speaks to the kids about economies. During his speech, Lisa informs Burns that, according to his biography, "Will There Ever Be a Rainbow?", Burns has less money than he thinks. Mr Burns then decides to check his savings and to do some investments, which are not as good as he thinks, but his lawyers don't want to confront him. After Mr. Burns' investments make him bankrupt, he realizes his lawyers were afraid of telling him he was making bad decisions. Since Mr. Burns lost all of his money, the bank forecloses on the plant and sells Mr. Burns' house to pro wrestler.

He lives with Waylon Smithers, Jr. for a short while, then gets put in the Retirement Castle. Soon, Burns begs for the help of Lisa, who had been pestering him (and the rest of the neighborhood) about recycling. She declines, but after patience and irritation, she gives in, on the condition that he will lose his evil manners. She helps him, and the two start making money recycling cans. After a while Mr. Burns has made enough money to open the Little Lisa Recycling Plant, all made from recycled materials. Lisa is pleased, believing that Mr. Burns has truly changed, until Burns show her 'the best part': he is using people's recycled plastic to create giant six-pack holder nets, 'cleaning the sea' by hauling all the creatures out of it, and selling the meat as animal slurry.

Lisa, appalled, tries to convince everyone to stop recycling, but they are apparently brainwashed. Lisa is comforted at home, and receives a visit from Mr. Burns, who informs her he's sold the Plant for $120 million. He offers 10% to Lisa as a reward for 'being his advisor', but knowing where the money came from, she turns it down.

Homer has four simultaneous heart attacks (thinking she turned down $12,000 dollars). She later corrects him in hospital, saying that 10% would actually be $12 million. Homer suffers another heart attack.

Production
The episode was directed by Mark Kirkland and written by John Swartzwelder. The writers had always thought about having an episode in which Burns lost all of his money and would have to interact with the outside world.

The producers have joked about this being the final episode of the series due to the episode ending with Homer suffering from another heart attack after Lisa tells Homer what 10% of Burns' $120,000,000 check really is. Two alternate original titles for the episode were Cohen's "Lisa and Burns" and Swartzwelder's "Burns Goes Broke".

Reception
In the I Can't Believe It's a Bigger and Better Updated Unofficial Simpsons Guide, the episode was called "An odd episode with a not-too-unexpected outcome. The best bits are undoubtedly Burns learning his way around a supermarket and Lisa's realisation of what Burns has been up to."