Finally reunited, Burnham and the U.S.S. Discovery crew journey to Earth, eager to learn what happened to the Federation in the last thousand years.

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

Michelle Yeoh (Philippa Georgiou)

Blu del Barrio (Adira)
Christopher Heyerdahl (Wen)
Adil Hussain (Aditya Sahil)
Phumzile Sitole (Captain Ndoye)
Kenneth Welsh (Senna Tal)

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)
Fode Bangoura (Alien Merchant)
Shawn Campbell (Supervising Inspector)
Riley Gilchrist (Andorian Regulator)
Xavier Lopez (Passing Crew Member)
Fabio Tassone (Book's Ship Computer)
David Benjamin Tomlinson (Lt. Linus)

• Saru is made acting captain in this episode, with Burnham agreeing to be his number one.
  
• Discovery heads to Earth to find an Admiral Senna Tal who left a message calling for Starfleet officers to meet with him.
  
• This episode introduces Blu del Barrio as Adira. She is a 16-year-old human who reveals she secretly carries the Trill symbiont that was formerly Admiral Tal. She should be able to access the symbiont's memories, but is unable to. Adira leaves Earth to go with Discovery. (Blu del Barrio is non-binary gender in real life, but the character Adira was not revealed to be non-binary and was referred to by a "she" pronoun.)
  
• At this point in the timeline, the fallout from The Burn caused Earth to leave the Federation and isolate itself, and the United Earth Defense Force now handles planetary security. The Federation and Starfleet left Earth 100 years prior.
  
• There's a nice moment at the end when the junior officers beam down to the former Starfleet Academy grounds.
  
• Wilson Cruz (Dr. Culber) and Rachael Ancheril (Commander Nhan) do not appear in this episode and their names do not appear in the opening credits.