Star Trek: Picard is set decades after the unthinkable: a disillusioned Jean-Luc Picard, former captain of the Enterprise, has left Starfleet, the fabled organization that represents his highest ideals. But in order to figure out why, we need to turn to what might be a surprising source for some Star Trek diehards.
Source: io9 – What We Know About the Disaster That Made Picard Quit Starfleet