On Christmas Eve at the Smith residence, absurdity is never in short supply. Jerry struggles hopelessly with hanging Christmas lights when Rick casually pulls out a ray gun and zaps him—"Makes your body lighter than air and your shoes heavier than lead," he explains, muttering through a cigar. "Wears off in ten hours, $30 for a refill." Jerry has just figured out how to hang the lights while floating when he shows off a jump, loses one shoe, and instantly becomes a drifting "human balloon." Meanwhile, Rick has already dragged Morty off on a space adventure.
The space trip begins with teenage rebellion and an old bastard’s irritability. Morty refuses to swallow Rick’s "anti-pee centipede" and insists on going outside the ship to pee. As soon as he opens the airlock, a snake wearing an astronaut helmet sinks its fangs into his ankle. This isn’t just any snake—it’s Snake Planet’s first interstellar explorer—and more ironically, the first female astronaut in snake history. Rick dispatches the snake cleanly and whips up an antidote. Glancing at the shaken Morty, he snorts: "These losers are too busy fighting a civil war over skin color. Extinction's just a matter of time—no need to feel guilty."
Rick’s mockery does nothing to ease Morty’s guilt. Back on Earth, he secretly buys a burly California kingsnake from a pet store, steals Rick’s spaceship keys, and sends it to Snake Planet, hoping to "replace" the fallen "heroic astronaut" for the snake race. He thinks it’s an act of goodwill, but little does he know this gesture is like a singularity in a chaotic system, detonating Snake Civilization’s fate entirely.
Snake Planet’s reaction exceeds Morty’s wildest imagination. Detecting the "alien snake’s" landing, they initially hail it as a genetically superior savior, urging it to breed with native snakes to create a braver clan. But the Earth snake’s wild nature clashes violently with Snake Planet’s civilization. When linguist snakes decipher its "ancient language," they accidentally discover it’s not one of them—instead of causing chaos, this revelation makes the snakes aware of an "alien threat." They immediately put aside their racial conflicts and mark Morty as an enemy to be eliminated.
Morty realizes he’s messed up big time when the first laser-equipped robotic snake crashes through the Smiths’ window. Rick surveys the snake-shaped debris and reconstructs the timeline perfectly: "Those snakes would’ve regressed to a primitive society after a few more generations of infighting. Your 'kindness' gave them the catalyst to evolve." No sooner does he finish speaking than more snakes pour through time—robotic snake assassins from 2026 and a "Snake Terminator" sent by the snake resistance. The former wants to kill Morty to eliminate future troubles, while the latter sees him as "the grandfather of the snake savior." In the chaos, Beth crushes the protective "Snake Terminator" with a single stiletto heel, making the scene absurdly suffocating.
Meanwhile, Jerry’s "floating adventure" continues. He refuses rescue from Rick and Beth, stubbornly declaring, "Either I survive on my own, or it’s your fault." To land, he clings to a tree’s canopy and climbs down, then luckily spots a nearby tavern—only to be thrown back into the sky by the unwelcoming patrons.
Rick takes Morty to 2026 Snake Planet, intending to destroy the snakes’ time machine, but finds they’ve only completed a quarter of it. "Procrastination's hereditary," Rick complains, then suddenly has a brainstorm—he sends a telepathic message to his future self. Minutes later, "Future Rick and Morty" appear, bleary-eyed, carrying a snake-language time machine manual and snake-skin disguise suits. It turns out they’ve just finished cleaning up this "mess" and are furious, eager to rant at their past selves.
The grandfather-grandson duo dons the snake-skin suits and travels to 1985 Snake Planet, slipping the manual into "Snake MIT." This act shatters the space-time balance entirely: after mastering time technology ahead of schedule, the snakes go on a rampage altering history—some travel back to assassinate Snake Lincoln, sparking the rise of Snake Nazis; others try to protect the first snake ancestor, only to trigger wars with snakes from other timelines. Snake Planet instantly becomes a slaughterhouse of temporal paradoxes, with countless snake figures flickering and vanishing in light beams as the entire civilization descends into a self-destructive carnival.
The chaos finally alerts the Interdimensional Temporal Authority. When Rick and Morty return to Earth, uniformed time cops have already traced back time, found, and killed the first primitive snake to use tools—this act erases Snake Civilization from existence at its root. All time-traveling snakes instantly turn to dust, as if they’d never existed.
As the Christmas lights illuminate, Jerry limps down from the roof, lying that he’d been hanging lights the whole time—only to trip down the stairs and break his leg when he turns them on. Rick heals him 50% with the ray gun, saying coldly, "Grow the rest back. Learn a lesson." Late at night, the grandfather and grandson fulfill their promise to their future selves in the garage—while translating the snake-language manual, Rick suddenly punches Morty in the face: "Next time you pull a stunt like this, it won’t just be dark circles you’re dealing with."