After the U.S.S. Enterprise completes a mission requiring several of the crew to become Vulcan, new problems arise when it is time for them to change back into humans.

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)

Paul Wesley (Lt. Cmdr. James Kirk)

Patton Oswalt (Doug)
Cillian O'Sullivan (Dr. Roger Korby)
Melanie Scrofano (Captain Marie Batel)
Mynor Luken (Beto Ortegas)
Carol Kane (Commander Pelia)

Rong Fu (Lt. Jenna Mitchell)
Graeme Somerville (Vice Admiral Pasalk)

• The Enterprise heads to Tezaar to repair a nuclear power reactor. The Vulcans made first contact with Tezaar before the forming of the Federation. With Enterprise the only ship available, the crew must appear as Vulcan to keep from breaking the prime directive.
  
• The mission is completed within the opening teaser. When they return to the ship, the cure does not work, and they are stuck as Vulcans.
  
• During the opening credits, Anson Mount recites the monologue in his "Vulcan" speech style.
  
• La'an confirms that she and Spock are "casually dating."