Leland reveals Section 31 built the Red Angel suit, and a trap using Burnham as bait reveals that the angel is her mother.
While the crew prepares Airiam's funeral, Tilly finds a scan of Burnham hidden in the code taken from Airiam. Leland admits that Section 31 developed the Red Angel suit for a temporal arms race with the Klingons, that Burnham's biological parents worked on the project, and that his carelessness led to their deaths in a Klingon attack.
The crew bets that the Red Angel always comes to save Burnham, so she lets herself die in a toxic atmosphere on Essof IV. The trap catches the angel, who revives Burnham, and Burnham recognizes her as her mother. Hanelle M. Culpepper directed.