While on a survey mission, the U.S.S. Enterprise discovers a comet is going to strike an inhabited planet. They try to re-route the comet, only to find that an ancient alien relic buried on the comet's icy surface is somehow stopping them.

As the away team tries to unlock the relic's secrets, Pike and Number One deal with a group of zealots who want to prevent the U.S.S. Enterprise from interfering.

Anson Mount (Captain Christopher Pike)
Ethan Peck (Lieutenant Spock)
Jess Bush (Nurse Christine Chapel)
Christina Chong (Lt. La'an Noonien-Singh)
Celia Rose Gooding (Cadet Nyota Uhura)
Melissa Navia (Lt. Erica Ortegas)
Bruce Horak (Lieutenant Hemmer)
Rebecca Romijn (Lt. Commander Una Chin-Riley)

Dan Jeannotte (Lt. Samuel Kirk)

Dana Beddoe (Deleb Alien Daughter)
Amber V. Cull (Deleb Alien Mother)
Jennifer Hui (Ensign Christina)
Alex Kapp (U.S.S. Enterprise Computer)
André Dae Kim (Chief Kyle)
Thom Marriott (Shepherd Captain)

• During Pike's dinner party, we learn a bit more about Uhura. After the death of her parents and brother in a shuttle accident, Uhura moved in with her grandmother. Hearing stories of her grandmother's time in Starfleet, she enrolled in Starfleet Academy. By the time she graduated from the Academy, Uhura spoke 37 languages, including Vulcan, Andorian, and all 22 native Kenyan languages.
  
• Hemmer is an Aenar, a subspecies of Andorian. They are blind with pale skin and have enhanced cognitive abilities. The Aenar were introduced in the Enterprise episode "The Aenar". (Actor Bruce Horak is legally blind.)
  
• Babs Olusanmokun (Dr. M'Benga) does not appear in this episode and he isn't credited in the opening titles.