Tensions rise as representatives from across the galaxy gather to confront the threat of the Dark Matter Anomaly. Zora’s new sentience raises difficult questions.

Sonequa Martin-Green (Captain Michael Burnham)
Doug Jones (Captain Saru)
Anthony Rapp (Lt. Cmdr. Paul Stamets)
Wilson Cruz (Dr. Hugh Culber)
Blu del Barrio (Ensign Adira Tal)
David Ajala (Cleveland Booker)

Ian Alexander (Gray Tal)
David Cronenberg (Dr. Kovich)
Shawn Doyle (Dr. Ruon Tarka)
Chelah Horsdal (President Laira Rillak)
Tara Rosling (President T'Rina)
Phumzile Sitole (General Ndoye)
Annabelle Wallis (Zora)

Andreas Apergis (Guardian Xi)
Nicole Dickinson (Orion Delegate)
Alex McCooeye (Emperor Lee'U)
Giovanni Spina (Provost Sta'Kiar)

• Mid-Season finale. (Star Trek: Prodigy will air during the break until Discovery returns February 10.)
  
• Tarka has developed a cascading subspace weapon, which Burnham deduces is an isolytic weapon, which have been banned by the Khitomer Accords for over 1000 years.
  
• The Son'a used isolytic weapons against the U.S.S. Enterprise in Star Trek: Insurrection.
  
• Ndoye returns, now promoted to General. Titan has join United Earth since she first appeared in Season 3's "People of Earth".
  
• Gray decides to return to Trill to start her guardian training. Adira goes with him to help him settle.
  
• Mary Wiseman (Sylvia Tilly) does not appear in this episode and her name does not appear in the main title opening credits. (However, she does appear in Zora's archival "dream" footage.)