The Smiths' breakfast table is never short of absurd openings—Rick casually builds a butter-serving robot, and the self-aware little machine, having just fulfilled its mission, immediately plunges into an existential crisis, huddling glumly in the corner. Meanwhile, Morty approaches Rick for help with his science project. Jerry, who’s always struggled with feelings of inferiority about his intelligence, jumps at the chance, volunteering to collaborate with his son on a solar system model to prove his worth. Morty can’t bear to refuse, so he agrees. On the other side, Summer asks her family to drive her to her new part-time job. Jerry, already wrapped up in his "scientific endeavor," passes the buck to Rick, who grumbles, "Would do literally anything except drive you" but reluctantly fires up the spaceship anyway.
Rick drops Summer off at an antique thrift store called "Necessities," run by a cranky old man named Mr. Ned. The newly opened shop exudes an eerie vibe—Mr. Goldfard, the math teacher who’d mistakenly wandered in thinking it was a juice bar, is greeted by his full name as soon as he steps inside and even receives a free bottle of aftershave supposedly guaranteed to attract women. Ned’s murmu r, "We never take money here," instantly puts Rick on high alert, and he bluntly accuses, "You’re a devil, aren’t you?" The accusation terrifies Ned, who hastily shoves a microscope into Rick’s hands. Pushed along by Summer, Rick leaves with a belly full of doubts. Little does he know, the microscope harbors a curse that lowers intelligence—and Summer, won over by Ned’s "kindness," has already decided to work at the shop.
Jerry and Morty’s collaboration is fraught with conflict from the start. While building the model, Jerry insists Pluto is a planet: "It was a planet when I was a kid, and it still should be." But Morty clearly remembers the scientific community reclassifying Pluto as a dwarf planet long ago. Unable to resolve their argument, Jerry impulsively calls NASA to debate. To his shock, an alien spaceship crashes through the window moments later, abducting the father-son duo to Pluto. There, they meet King Flippypips, ruler of Pluto, who is overjoyed by Jerry’s claim that "Pluto is a planet." He immediately packages Jerry as an "Earth scientist" and has him deliver a live nationwide address to affirm, "We are still a planet." The sudden adulation inflates Jerry’s ego to unprecedented heights—he soaks up the cheers of the crowd, completely oblivious as a Pluto scientist pulls Morty aside.
The scientist reveals a brutal truth to Morty: Pluto’s leaders have been secretly mining the planet’s core resources, causing it to shrink drastically—that’s the real reason it lost its planetary status. They’d brought Jerry in solely to use his rhetoric to cover up the planet’s decline. Morty hurries to tell Jerry the truth, but by then, Jerry is already drunk on fame and fortune. He not only ignores Morty’s warnings but also mocks him publicly at a fancy gala, and even turns a blind eye as the scientist (who’s actually the king’s son) is thrown in jail for exposing the truth. It isn’t until Jerry stands on the stage of Pluto’s "Bell Prize" ceremony, staring into the hopeful eyes of the crowd, that he suddenly remembers Morty’s disappointed face. Finally coming to his senses, he shouts into the live camera, "Pluto is not a planet!" Enraged, the Plutonians promptly banish him, and the father-son pair return to Earth in disgrace—though Jerry’s eyes hold a newfound clarity.
Back on Earth, chaos is escalating. Goldfard tracks down Rick with a side effect of the aftershave: while it did attract women, it left him infertile. After curing him with his technology, Rick logically invents a handheld curse-detecting device and storms back to "Necessities." He publicly scans all the merchandise, revealing their vicious curses: a comb that causes hair loss, a scarf that triggers claustrophobia… The customers flee in terror, and Ned flies into a rage, tackling Rick. To Rick’s surprise, Summer sides with Ned, shoving him out of the shop. Betrayed by his daughter, Rick refuses to back down—he immediately opens an "Anti-Curse Shop" across the street, specializing in removing curses from demonic artifacts. The business booms, driving Ned’s shop out of business.
As a devil, Ned has never experienced failure. Crushed by the loss of his dignity, he attempts suicide—luckily, Summer saves him just in time. Seeing Ned’s dejected state, Summer feels compassion and encourages him to leverage his talent for "creating curses" to start a new business. With Summer’s help, Ned launches "Cursed Fitness Classes," a hit with the slogan "Pain for Muscle," and even catches the eye of Google, which plans to acquire the company. However, once he achieves success, Ned betrays Summer, kicking her out and taking all the credit for himself. Furious at the betrayal, Summer turns to Rick—and for the first time, grandfather and granddaughter form an unlikely alliance. They hit the gym relentlessly, building massive muscles before crashing Ned’s acquisition press conference. In front of all the media, they thoroughly beat up the ungrateful devil.