With the Captain away and much of the crew on shore leave, Lt. Spock decides to steal the Enterprise to come to the aide of a former crew member warning of a threat to the Federation on the edge of Klingon space.
With Enterprise's first officer Commander Una Chin-Riley on trial for lying to Starfleet about her genetic modifications, Pike turns to one of her oldest Illyrian friends to defend her.
After finding herself on an alternate version of the Enterprise Lt. Noonien-Singh travels back to twenty-first century Toronto, along with Captain James T. Kirk, to try and restore the timeline.
Captain Pike leads an away mission to Rigel VII following evidence that a mission that went horribly wrong five years earlier resulted in cultural contamination. But once on the surface, the team finds their memories slipping away from them.
After a shuttle accident Spock awakens to find that a mysterious alien race has left him fully human ... on the eve of his ceremonial engagement dinner with T'Pring's family.
Uhura is plagued by an unusual communication inside a stellar nursery that only she can hear, leading to disturbing hallucinations. Number One works with Pelia to bring a deuterium refinery online, and James Kirk visits his brother on board Enterprise.
When Ensign Brad Boimler accidentally travels to the twenty-third century from the future, the Enterprise crew must help get him back before he accidentally alters the timeline.
Enterprise plays host to a Klingon dignitary who has defected from the Empire, raising tension among members of the crew who served in the war – and unearthing a troubling secret from Dr. M'Benga.
The ship's proximity to a subspace fold entangles the crew with a musical reality, prompting them to break into song to express heightened emotions ... and threatening the quadrant. Meanwhile, La'an considers telling Lt. Kirk the truth about their past encounter.
Captain Batel and the crew of the Cayuga are caught off guard when the Gorn invade a peaceful human colony, and the Enterprise responds with a risky rescue mission.
