On his way to broker a peace deal with two renegade Klingon houses, Vulcan ambassador Sarek is injured when a "logic extremist" attempts to assassinate him. On board Discovery, Burnham — who is linked to Sarek's katra — collapses. Recovering, she urges Lorca to help rescue her adoptive father, and he agrees. Burnham enters a nebula in a shuttle with Tyler and Tilly, where she attempts to connect with Sarek. In his mind, she sees the time Sarek informed her that the Vulcan Expeditionary Group had rejected her application, but he expels her from his mind. Realizing he is hiding something, she confronts him and he admits that the VEG would only admit one of his children so he chose Spock, who ultimately joined Starfleet, rendering his decision futile. With their mental connection established, Burnham revives Sarek and he activates an emergency beacon.
Admiral Cornwall arrives on Discovery to assess Lorca's psych evaluations. The two sleep together, but Cornwall is concerned by Lorca's paranoid behavior and threatens to stand him down as Discovery's captain. With Sarek too injured to meet the Klingons, Lorca suggests Cornwall take his place, however the peace talks are a trap, and she is taken captive.