The Scorpion's Tale (Episode 15)

Bart and Lisa's class took a field trip a park in the desert. Lisa took a walk into the desert when she was attacked by two Scorpions, but found out that  a certain flower calmed them down. Her plan was to take them back a research why that occurred. Grandpa is also kicked out of the nursing home and is forced to live back at the Simpson home, but is causing problems. Homer sees what Lisa is doing and comes up with the idea of using the flower on Grandpa. The next morning, Grandpa drinks the coffee and is in a much friendlier mood. This untested drug that makes Grandpa happy concerns Lisa because she doesn't think it is safe, so she flushes the drug into the ocean. A German scientist figures how to recreate the drug and begins to sell it to the public.Bart has a prototype of the drug and begins selling it to everyone, so the people of Springfield are all much happier. The side effect of eyes falling out begins to happen, so the medical company wants to destroy the drug. The episode ends with Grandpa and everyone from his generation working together to fix the problems that the younger generation caused.