After a bad experience with genetically modified food, including baby corn the size of ordinary corn and a potato that eats Lisa's carrots, Marge decides to plant her own garden. Crows arrive on the new garden, so Marge makes a scarecrow, which scares Homer. Homer destroys the scarecrow, and the crows eventually see Homer as their leader, following him everywhere and doing his bidding, much to the dislike of his family and friends who find the large flock of birds constantly surrounding Homer to be disturbing. However, things soon turn sour when Homer tries to drive off the crows after they try to carry Maggie, and she falls out of her onsie, only saving herself by using her diaper as a parachute. When Homer yells at the crows to leave, they turn on him and peck at his eyes. He then goes to the hospital, where Dr. Hibbert prescribes him medicinal marijuana for the pain. Having had a bad experience with marijuana when he was younger (said "experience" is shown to be being mauled in the crotch by a police dog after hiding a marijuana joint belonging to Lenny and Carl in his pants), Homer objects to Hibbert's suggestion at first, but eventually decides to try it.
Homer finds himself enjoying the experience immensely, seeing the world as a magical place, and even enjoying things he hated before, such as Lisa's saxophone playing. He even asks Flanders to read him the whole Holy Bible, much to Flanders' excitement. When Flanders offers a petition to have a vote on the ban of medical marijuana in Springfield, Homer unwittingly adds his signature. Homer's stoned state also sees him promoted to Executive Vice-President at the power plant, because Mr. Burns appreciates how Homer laughs at all of his lame jokes, and so he goes to a rally for the legalization of medical marijuana (but the rally is actually held a day after the ban was approved by voters). Homer's eyes have healed and agrees to stop smoking pot after Marge tells him he needs to set a good example for his kids.
Mr. Burns asks Homer to help him with a speech for a crisis shareholders meeting, where the SNPP must raise millions of dollars or be forced into closure, due to Mr Burns having "pissed away" their funds. Homer gives Smithers his last joint, and while Smithers is smoking and dressing in the coat Judy Garland once wore, Burns apparently drowns in his bathtub. Smithers tells Homer they have to make it to the meeting. When Homer points out that Mr Burns is dead, Smithers tells him that it doesnt matter, its apparently a fairly common issue with corporate figures. He cites examples such as Michael Eisner having been dead for five years, and Ted Turner just being a hologram. So, for the meeting, Smithers and Homer make Mr. Burns into a marionette, à la Weekend at Bernie's, and the movement of the marionette inadvertently gets Mr. Burns' heart working again. The shareholders are mollified and pledge renewed funding, and another financial crisis at the power plant is avoided.