Conspiracy
After another adventure, Rick, Morty, and Summer fall through the portal back into their garage, just as Jerry appears at the garage door to say goodbye to his children. Although Morty tries to talk to his father, Summer ignores him and asks Rick to take her somewhere else, with Morty reluctantly joining them. Beth arrives at the garage looking for Morty and Summer, but immediately leaves after seeing Jerry. As Jerry stands mournfully in front of the house, the wind silently calls him a loser.
Rick’s portal takes him and his grandchildren to a diesel-powered post-apocalyptic Earth filled with dieselpunk cars, shotguns, mutants and cannibals. Rick’s main goal is to obtain the powerful isotope-322, but the adventure is diverted when Summer falls in love with this dimension, kills the leader of the Death Stalkers and forms an alliance with them. Although Rick and Morty initially want to go home, Rick sees that the Death Stalkers have a large rock form of Isotope-322 and decides to stick around so he can steal it.
While Summer goes off to kill some people, Rick tries to distract Morty by ringing the bell in the Thunderdome (or Blood Dome as the Death-Stalkers call it). Rick injects a serum that extracts muscle memory from body parts into Morty’s arm to give him fighting skills, but the “muscle memory” apparently includes the memories and personality of said body parts, giving Morty a left arm with massive strength that punches Rick before punching him . and killing various death stalkers in the Blood Dome. Although Morty does this against his will at first, he soon begins to take out his frustrations on Jerry for agreeing to a divorce through his hand. Rick tries to get Morty and Summer to leave before the Death-Stalkers notice that someone stole the Isotope-322, and Morty’s arm reveals the theft, forcing Rick to pull out his laser pistol and tell the viewer he’ll be right back.
The episode continues with Rick being chased by his grandchildren in separate cars. He tries to convince them that they’re only staying in the world because they don’t want to face their parents’ divorce, but eventually gives up and goes back to his garage, leaving Morty and Summer trapped (albeit willingly) with the Death Stalkers.
While in the Blood Dome, Morty’s arm recognizes the soldier who killed his wife and children before torturing him and proceeds to chase him out of the Blood Dome and kills him. With an arm that wants revenge on the soldier’s boss, Morty is forced to come. Meanwhile, Summer develops a romantic relationship with the new leader of the Death Stalkers, a guy with a bucket on his head named Hemorrhage.
Wanting to hide his absence from Beth, Rick sets up several Morty and Summer robots to trick and cheer Beth, but they only succeed in making her cry and leave to call Jerry.
Morty and his arm, now nicknamed “Armothy”, prepare to exact revenge on the soldier’s commander. Morty tries to convince Armothy to put his revenge on hold so he can continue venting his frustrations about the divorce, but he soon realizes that, like Armothy, he must learn to move on. He begins choking the man to death just as Rick comes to get him, admitting that it would be too hard to find another Morty and Summer to cheer Beth up. He then helps Morty complete Armothy’s murder victim.
Rick and Morty meet up with Summer and Hemorrhage and offer Isotope-322 and his powers as a peace offering. Hemorrhage asks him for help rebuilding the company, to which Rick agrees, ostensibly as a way to avoid dealing with his daughter’s divorce. Three weeks later, the post-apocalypse has morphed into something resembling modern suburbia, with Summer stuck in an unfulfilling marriage to Hemorrhage—a marriage similar to Jerry and Beth’s.
Frustrated, Summer agrees to return to her Earth with Rick and Morty, realizing that Rick planned the whole thing to teach her that she can’t run away from her problems at home. As they leave, Rick steals the last isotope-322, ultimately sending the post-apocalypse world back to where it started before the trio intervened.
The trio return to their house just as Rick’s robot Morty, made to distract Beth, gains sentience, trying to fight his programming and stay alive, only for his programming to be overwritten before the robots are destroyed by the originals.
“I want to be alive! I am alive! Alive, I tell you! Mother, I love you. It’s not just words anymore. I want to hold you I want to run in the flow. I want to taste the ice cream, but not just put it in my mouth and let it slide down my throat, but really eat it.”
— Mechanical Morty
Morty remarks to his mother that if Jerry really wanted to stay, he’d fight to make it happen: in the end, he doesn’t care, or he’s not strong enough. Summer visits Jerry and gives him the skull of the first mutant she killed, the creature that made the mistake of looking back while running away, as a reminder not to look back.
In the post-credits scene, Jerry tries to get his unemployment check from the post office, but is confronted by a wolf who threatens him and chews the check, apparently just to make him suffer. The wind calls him a loser again.
