The overarching plot of "Rick and Morty" is driven by Rick C-137's hidden trauma: the murder of his wife, Diane, and young daughter, Beth, by another Rick variant, Rick Prime. This event, confirmed in the Season 5 finale "Rickmurai Jack," is the catalyst for his entire character. His invention of portal travel was not for science, but for revenge. To facilitate his hunt, Rick helped create the Central Finite Curve, a walled-off section of the multiverse containing only universes where he is the smartest man alive, thus narrowing the search for his nemesis.
The character known as 'Evil Morty,' introduced in Season 1, is revealed to be a Morty who became aware of his predetermined role as a sidekick and shield for a Rick. His entire multi-season plan, which involved becoming president of the Citadel of Ricks, was a meticulously crafted plot to gather the resources and information needed to breach the Central Finite Curve. In the Season 5 finale, he succeeds, escaping into the true, untamed multiverse where Ricks are not guaranteed to be the dominant force, achieving a form of ultimate freedom.
Rick C-137's quest for vengeance culminates in Season 7's "Unmortricken." With the help of Evil Morty, he finally tracks down and kills Rick Prime. However, the victory is profoundly empty. Having defined his life by this singular goal for decades, Rick is left without a purpose, plunging him into a deep depression. This act fundamentally restructures the series, moving it away from the central revenge plot and towards a new narrative focused on Rick finding a reason to live beyond his trauma and hatred.
Another significant plot point is the existence of Space Beth. In Season 3, Rick creates a clone of Beth, sending one to have adventures in space while the other remains on Earth, and then deliberately erases his memory of which is the original. This forces both Beths, and the family, to accept the ambiguity of their identity and to value each other as individuals, regardless of their origin.