"Raging Abe Simpson and His Grumbling Grandson in "The Curse of the Flying Hellfish"" is the twenty-second episode of Season 7. It aired on April 28, 1996. The episode was written by Jonathan Collier and directed by Jeffrey Lynch. It is also the 150th episode overall.
When Reverend Lovejoy holds a funeral, Abe Simpson and Mr. Burns are the only people there. They open a safe with keys and pull out a piece of paper with names on; they cross Asa Phelps name which leaves Grandpa Simpson's name and Monty Burns'. Mr. Burns and Abe Simpson then start discussing the 'Hellfish Bonanza' (while doing so Abe humiliates himself 3 times).
When back at his mansion, Mr. Burns orders assassin Fernando Vidal to murder Abe Simpson so he can get his key to the safe. Several attempts at killing Abe Simpson fail including a Simpsons family impersonation and just straight trying to gun him down with a machine gun in the retirement castle. Grandpa runs to the Simpsons house and comes in. He tells the family the story of his near deaths without explaining why. Lisa, Marge and Homer agree that he will stay in Bart's room, much to his disappointment since he wanted him sleeping in the garbage. In Bart's room, Abe Simpson describes to Bart why Mr. Burns is trying to kill him.
Abe Simpson tells a story about the Hellfish Bonanza and the agreement that the survivor would inherit some ancient paintings. When Mr. Burns crashes through Bart's room, Abe hands over his key in fright. Bart jumps up to him on his crane (which crashed through Bart's room with Mr. Burns on) and asks if he can come but Mr. Burns rejects due to the "Child Labor people watching [Burns] like a hawk." He then leaves the house laughing (although not before accidentally smashing the adjoining wall into Lisa's room). Bart then reveals that he stole the keys from Mr. Burns.
After some persuasion, Bart finally convinces Abe to get the treasure. When they tell Homer what they are doing, he asks if he can come but Abe convinces him not to. When Bart and Abe find their safe at the graveyard. A light on the top of the memorial points out to the sea. Bart goes to 'borrow' some diving equipment while Abe steals a Speedboat from the Flanders House (although Flanders' reaction implied that he loaned it to them willingly).
They race out in a Speedboat towards the light. When they arrive at the light, Grandpa tells Bart to tug on the rope '63 times if he's out of air' and '64 times if he's got the treasure'. Bart finds the treasure and tugs the rope 64 times. Grandpa opens the treasure and finds the treasure. Suddenly, Mr Burns arrives on the boat and steals the paintings. He kicks Bart into the crate which then falls to the bottom of the sea. Grandpa goes down and successfully saves Bart. They then chase down Monty and catch him on the shore. Grandpa gets the paintings but then the State Department intervene and take the paintings away for Baron von Herzenberger, their rightful owner.
Grandpa tells Bart "That at least he got to show he wasn't always a pathetic old kook". Bart replies by saying, "You never were". They then embrace as the episode ends (though the Baron stops to tell them to "get a room").
The episode was written by Jonathan Collier and directed by Jeffrey Lynch. Jonathan Collier got the idea of the episode after reading about how famous paitings have been rediscovered years after their so-called disappearance. Jeffrey Lynch had assistance with the episode from Brad Bird, a former animation director who worked on the Simpsons who is now known for his work with Pixar Animation Studios and his films The Incredibles and the Iron Giant.
The episode was heavily praised for its animation, most of which was underwater. The "ripple" effects were added in post-production.
The episode is also the first time we see the fathers of many Springfield men.
The authors of the book I Can't Believe It's a Bigger and Better Updated Unofficial Simpsons Guide, Warren Martyn and Adrian Wood, wrote that the episode is "notable for Mr Burns' impersonation of Marge, some spectacular action sequences, and some good underwater scenes - but it is not especially brilliant"