Michael Burnham. And here's how it might happen:
Michael decides her biggest mistake was not taking over the Shenzhou earlier and contacts a newly promoted Starfleet admiral (they keep dropping like glob flies) to demand command of the Discovery. After being rebuffed because she is literally a mutineer who should be in prison and once again not getting her way, Michael angrily storms back to her room. Tilly tries to cheer her up by laughing awkwardly, but Mikey isn't buying her friendly persona anymore and suspects Tilly of being a Klingon spy. She reminisces about Philippa's death, and decides to go look out into space with her telescope. Acting impulsively, she points the telescope at a nearby star and destroys her eye. Dr. Culber proceeds to treat her while suggesting she be more careful in the future. Who the hell does he think he is lecturing me? He's not even the damn CMO, she thinks. Lounging nearby, Stamets makes a snarky remark while chowing down on shrooms. He'll be the first to go when I take control of the ship. Lorca calls her to the bridge because he can't be caught having a conversation with one of the extras and his BFF Ash is always hanging out in the mess hall for some reason. After discovering that Burnham might steal his spotlight by also having an eye injury, he orders her NOT to go on a diplomatic mission to negotiate peace with the Klingons. So she steals a shuttle and heads off immediately. Saru contacts her to warn that he senses a trap. She calls him a coward and says her agent promised that she only has to do 3 seasons before she can leave to do movies so it can't be a trap. The mission turns out to be a trap. The mastermind is Harry Mudd who plans to capture and sell her to a group of miners who have empty nest syndrome because all of their kids moved offworld and they miss having an angsty teenager around. But before he gets the chance, his pet throws off its disguise to reveal it was Voq the whole time and he subsequently bores her to death by eulogizing T'Kuvma with a short speech that takes him several days to deliver. Sarek is then slightly disappointed that he has no one to talk to, but he doesn't really show it.
The End.