Grampa Simpson has lost his mind and is staying at the Calmwood Mental Hospital. Homer decides to pull him out for the day, but Grampa doesn't know what's going on and doesn't want to go. They drive to the Simpson house where Homer has a sick and devious plan. Homer places the moves on Grampa. Grampa still doesn't know what's going on and Homer takes full advantage of that. Homer thinks Grampa is gorgeous.