Georgiou is dying, and on the planet Dannus V a mysterious man named Carl sends her back to the mirror universe of her past.
Dr. Kovich tells Culber that Georgiou's body is breaking down because her molecules have drifted too far from their own time and universe. Georgiou and Burnham travel to the uninhabited planet Dannus V, where they meet a man named Carl guarding a door.
Georgiou steps through it and finds herself back in the mirror universe during her rule as emperor, with a chance to use what she has learned. Meanwhile Stamets and Adira use SB-19 data to trace the Burn to the Verubin Nebula, where they find a Kelpien distress signal. Omar Madha directed.