Discovery ventures to the Verubin Nebula, where Burnham, Saru and Culber make a shocking realization about the origin of the Burn. The rest of the crew faces an unexpected threat.

Avaah Blackwell, Bill Irwin, Emily Coutts, Ian Alexander, Janet Kidder, Oded Fehr, Oyin Oladejo, Patrick Kwok-Choon, Ronnie Rowe Jr., Tig Notaro