Georgiou uncovers the true depths of the plot against her, leading her to a revelation about how deeply her time on the U.S.S. Discovery truly changed her.

Sonequa Martin-Green (Commander Michael Burnham)
Doug Jones (Captain Saru)
Anthony Rapp (Lt. Cmdr. Paul Stamets)
Mary Wiseman (Ensign Sylvia Tilly)
Wilson Cruz (Dr. Hugh Culber)
David Ajala (Cleveland Booker)

Michelle Yeoh (Philippa Georgiou)

Oded Fehr (Admiral Charles Vance)
Blu del Barrio (Adira Tal)
Hannah Cheesman (Lt. Commander Airiam)
Paul Guilfoyle (Carl)
Daniel Kash (Duggan)
Tig Notaro (Cmdr. Jett Reno)
Rekha Sharma (Cmdr. Ellen Landry)

Emily Coutts (Lt. Keyla Detmer)
Patrick Kwok-Choon (Lt. Gen Rhys)
Oyin Oladejo (Lt. Joann Owosekun)
Ronnie Rowe Jr. (Lt. Ronald Bryce)
Sara Mitich (Lt. Nilsson)

• Carl reveals himself as the Guardian of Forever, previously seen in the classic Trek episode "The City on the Edge of Forever", and again in the animated episode "Yesteryear".
  
• He mentions the Temporal Wars, where he was used by others to cause damage to the timeline, so he went into hiding. The sphere data was able to extrapolate his position regardless.
  
• The Guardian sends Georgiou through the doorway, back to a point in time where the Prime and Mirror universes are still aligned.
  
• With this episode, Michelle Yeoh leaves the series.