Lethe

Sarek is travelling to peace talks with Klingon houses when a Vulcan logic extremist on his ship detonates a bomb. Burnham feels the attack through their telepathic link, and Lorca agrees to a rescue. With Tyler and Tilly, she takes a shuttle into a nebula and uses the bond to reach Sarek's mind. There she finds him reliving the day her application to the Vulcan Expeditionary Group was rejected, and learns the truth: Sarek was told only one of his children could be admitted, and he chose Spock, who then joined Starfleet anyway. Burnham pulls Sarek back to consciousness and he is rescued. Admiral Cornwell comes aboard to question Lorca's methods. After a night together, his violent reaction to being woken convinces her he should be removed from command. With Sarek unable to attend the talks, Cornwell goes in his place, only to be taken prisoner by the Klingons.