The DMA approaches Earth and Ni’Var. With evacuations underway, Burnham and the team aboard the U.S.S. Discovery must find a way to communicate and connect with a species far different from their own before time runs out.

Sonequa Martin-Green (Captain Michael Burnham)
Doug Jones (Captain Saru)
Anthony Rapp (Lt. Cmdr. Paul Stamets)
Mary Wiseman (Lieutenant Sylvia Tilly)
Wilson Cruz (Dr. Hugh Culber)
Blu del Barrio (Ensign Adira Tal)
Tig Notaro (Commander Jett Reno)
David Ajala (Cleveland Booker)

Oded Fehr (Admiral Charles Vance)
Stacey Abrams (President of United Earth)
Shawn Doyle (Dr. Ruon Tarka)
Chelah Horsdal (President Laira Rillak)
Tara Rosling (President T'Rina)
Annabelle Wallis (Zora)
Hiro Kanagawa (Dr. Hirai)
Phumzile Sitole (General Ndoye)

Emily Coutts (Lt. Cmdr. Keyla Detmer)
Patrick Kwok-Choon (Lt. Cmdr. Gen Rhys)
Oyin Oladejo (Lt. Cmdr. Joann Owosekun)
Sara Mitich (Lt. Cmdr. Nilsson)
Raven Dauda (Cmdr. Tracy Pollard, MD)
Orville Cummings (Lieutenant Christopher)
David Benjamin Tomlinson (Lieutenant Linus)
Seamus Patterson (Cadet Harral)
Adrian Walters (Cadet Taahz Gorev)
Michael Chan (FHQ Ops Officer)
Emmanuel John (FHQ Security Officer)
Jean-Paul Najm (FHQ Security Guard)
Fabio Tassone (Book's Ship Computer)

• Season 4 Finale.
  
• Mary Wiseman (Sylvia Tilly) returns, last seen in the 4th episode "All Is Possible". She and her cadets assist Federation HQ in the evacuation of Earth.
  
• The U.S.S. Mitchell NCC-325027 (Merian-class) assists in the evacuation of Titan and Earth. It is named for actor Kenneth Mitchell, who played Klingon General Kol in the first season.
  
• This episode debuted simultaneously with the Picard episode "Assimilated".