Sex gets in the way of Bud studying for his finals, and he risks being expelled when he is caught in the school library.

Lois and Clark go to Lois' high school reunion, and there, she finds out about the disappearing of two of her classmates' lovers. They are disappearing because another classmate of Lois wants revenge for her bad school time, then she's shrinking their ex-colleagues' mates. She hates Lois, and puts Clark as the next on her shrink list. Now, Lois needs to find out what and who is doing this, or Clark will be small until disappear.

Bart brings Abe to school in a special day for grandparents and he proceeds to embarrass Bart by lying. Abe gets a piece of mail saying that the seventh Hellfish is dead; this leaves only two of the Flying Hellfish left alive. When one is left, he will get to claim the legacy of art treasures they kept from the WWII. Who is the other Hellfish who hasn't died? Why it's Mr. Burns. Abe doesn't trust Mr. Burns, who is scheming on how to steal the treasure. Mr. Burns hires a world-famous assassin to take care of Abe, but none of the attempts work. When Abe goes to tell Homer and the family his tale, they do not believe him. Abe stays in Bart's room until the coast is clear. Abe tells Bart the story of the Hellfish, where he used to be ranked above Mr. Burns. Bart is highly skeptical. Mr. Burns comes in the night to steal Abe's key. When Bart sees this, he decides to help Abe stop Mr. Burns from taking the treasure. They take the Flanders' boat and go diving for it. After Bart brings it up onto the boat, Mr. Burns takes it from them and the he tries unsuccessfully to drown Bart. Abe and Mr. Burns have a scuffle on the shore and Abe wins. Just as Abe gets set to take the treasure, the authorities come to take the treasure back its rightful owner, a rich German.