Stranded on a toxic moon, Ortegas must defy her deepest beliefs to survive.

Anson Mount (Captain Christopher Pike)
Ethan Peck (Lieutenant Spock)
Jess Bush (Nurse Christine Chapel)
Christina Chong (Lt. La'an Noonien-Singh)
Celia Rose Gooding (Ensign Nyota Uhura)
Melissa Navia (Lt. Erica Ortegas)
Babs Olusanmokun (Dr. Joseph M'Benga)
Martin Quinn (Lt. Montgomery Scott)
Rebecca Romijn (Lt. Commander Una Chin-Riley)

Alex Kapp (U.S.S. Enterprise Computer)
Warren Scherer (Gorn)
Dariush Zadeh (Metron)

• The plot of this episode is similar to the Next Generation episode "The Enemy" and the Enterprise episode "Dawn" and the feature film Enemy Mine.
  
• It is revealed the Metrons trapped Ortegas with the Gorn to study them. They will continue this study in the Original Series episode "Arena"
  
• Jess Bush (Chapel), Babs Olusanmokun (M'Benga), and Martin Quinn (Scott) do not appear in this episode.