Its been reported over and over, and possibly disavowed when Fuller departed, that Discovery is based on an incident in Trek's past. So what might that be? My candidate - "disastrous first contact with the Klingons leading to decades of war" per Captain Picard. YES, well aware that Enterprise's own pilot started with the Klingon first contact, but i would argue that Burnham's actions are a version of "first contact", perhaps with the ancient ship Klingons, and seem to have been literally disastrous. Other candidates?