Morty asks Rick to synthesize a love serum keyed to his DNA so he can win over his classmate Jessica. When Jessica turns out to have the flu, the serum goes airborne at the school dance and infects the entire planet, leaving every unrelated person violently devoted to Morty. Rick's two attempted antidotes — praying mantis DNA, then a cocktail of seven other species — don't reverse the effect, they compound it, ultimately mutating the global population into disfigured humanoid creatures Rick calls Cronenbergs. With the world irreversibly ruined, Rick scans the multiverse for a dimension where their alternate selves fixed everything and then conveniently died, and the two slide into that vacancy, burying their own corpses in the backyard.

This episode marks the first hard reset of the series and establishes that consequences in Rick and Morty ...