Scenes from a hot desert planet where inhabitants go about their lives.

Uhura voiceover, recording a cadet’s log. The Enterprise is in the Persephone System observing a comet, C-22-60-Quentin. She is doing rotation and landing party readiness protocols. She’s excited about being invited to dinner at the Captain’s Cabin. She wears her dress uniform and finds out Ortegas was joking when she encouraged it.

Ortegas mentions it’s a square on Enterprise Bingo.

They arrive at the Captain’s Cabin and are greeted by Pike and Una. Uhura tries to settle in and sees Hemmer cutting vegetables. She offers to help which offends him. Spock serves as cultural interpreter for Hemmer who is Einar. Hemmer is grumpy.

Uhura decides Hemmer and Spock are hazing her as well and walks away after scolding them in Aenar and Vulcan, respectively.

Pike regales his guests with a story about why Security wasn’t a good fit for him. Spock asks about laughing at others’ misfortune.

PIke hears Uhura humming a song and asks about it. She shares that it’s a folksong from her village in Kenya. He discloses that he’s visited a place near where she grew up.

He comments on how only a few cadets ever get to serve on the Enterprise. He asks about her skills which include speaking 37 languages, including the 22 in Kenya alone.

He asks where she sees herself in ten years, catching himself slightly when asking.

She admits that she isn’t sure that Starfleet is her calling, which is met with some shock by those around. Pike points out she worked hard to get to the Enterprise. Spock contributes that she beat out several thousand applicants.

She explains that she planned on studying alien languages at the university in Nairobi where her parents taught, but just before she started, her parents and older brother were killed in a shuttle accident. She couldn’t handle going to the university campus so she enrolled in Starfleet on her grandmother’s suggestion.

Uhura and Spock walk together after the dinner and she asks if she blew it. Spock points out that honesty is valued by himself and the captain. He also reminds her that Starfleet is a dream for many and advises that if she is unsure about her career, she should step aside for someone who truly wants to be there.

Una comments on Pike’s verbal stumble as they clean up after the dinner. He reveals that he knows the names of the officers he saves when he is injured in ten years. She refuses to believe that there isn’t another way for the future to play out.

Spock summons Pike to the bridge because there is a problem with the comet.

The comet is on course to collide with Persephone-3, the planet from the opening scenes. It will be destroyed in two days when the comet strikes.

Pike asks for solutions. Una posits they move the comet off its course. Spock and La’an offer possible methods for making this happen. When they launch the ion engines at the comet, the incoming torpedoes are destroyed by a force field.

In scanning the comet, there is no sign of life but Una reports a mostly subterranean structure. Spock suggests they beam to the comet’s surface to investigate the structure. He leads a team with Sam, La’an, and Uhura. Chapel hits them with a hypospray to protect them from the cosmic radiation for two hours.

They beam to the comet’s surface and approach the structure.

While La’an sweeps the perimeter and Spock scans the interior, Uhura and Kirk approach an object in the center of the chamber. It’s covered in markings and Kirk encourages Uhura to examine and analyze them. She realizes they repeat in a sequence. Spock and La’an rejoin the group. Kirk approaches the egg on the top of the object, causing it to light up. A build up of energy blasts out and knocks him off the platform.

His heart has stopped but Chief Kyle is unable to beam them back to the ship. Spock turns his tricorder to defibrillator mode and resuscitates Kirk. La’an realizes they are cut-off from the ship by the comet’s force field.

Spock gives Uhura the responsibility of deciphering the marking in the chamber as the only linguistics expert on the team.

On Persephone-3, the inhabitants notice the comet.

On the ship, Ortegas suggests using phaser harmonics to break through the force field.

On the comet, Uhura tries to joke to break the tension. Spock advises rigorous logic.

On the ship, they are hit with weapons fire just before attempting to phaser the force field. They are hailed by a species in a very big ship. They are the Shepherds. They escort the comet, which they have named M’hanit and worship as an ancient arbiter of life. They warn Pike that if the Enterprise interferes with the comet again, the Shepherds will destroy them. They believe M’hanit’s effects are preordained and interference is wrong.

Pausing communications, Pike confers with Una and Ortegas and discovers the Shepherds’ ship outmatches the Enterprise on every level.

Pike returns to the communication link and explains they mean no disrespect as they try to save the inhabitants of Persephone-3. The Shepherd scolds them for the landing party already on the comet’s surface and states that any attempt to rescue them will be an act of war.

Spock tries to give Uhura a pep talk when he notices her humming out of anxiety. Later, he notices that the chamber’s light responds to her voice, the music.

On the ship, Una identifies a signal from the comet. The computer identifies it as the song Uhura hummed at the dinner party.

In the chamber, Uhura deciphers the markings as harmonics and with Spock singing backup, they unlock the egg with a major chord in variations.

As they discuss how to communicate with the comet to ask it to lower its force field, the chamber emits some music. Uhura sings it back and the shield comes down. Kyle beams them back to the ship and Pike prepares to engage with Shepherds. Instead, they hail the Enterprise and scold them once more before firing torpedoes at the ship.

The Enterprise manage to land a hit on the Shepherds’ ship. In the respite, Spock suggests getting the comet to move itself.

With Ortegas at the helm, the Enterprise flies into the comet’s debris field with the Shepherds in pursuit. Coming to a stop between the comet and the Shepherds’ ship, they shut down everything except life support and surrender to the Shepherds, asking for their help.

As the Shepherds activate their tractor beam, Spock launches his shuttle from a nearby asteroid. He flies by the nucleus of the comet with the shuttle’s shields radiating heat at maximum intensity, causing pieces of the comet to break away from the nucleus. The change in matter causes the comet to change trajectory so that it misses the planet.

The material that breaks off the comet enters the planet’s atmosphere, adding a large amount of water vapor to the atmosphere permanently, reducing the aridity. Spock theorizes this will make the planet more amenable to agriculture and societal development. Pike wonders if M’hanit actually brought life to Persephone-3 as the Shepherds believe it to do.

The Shepherds hail Enterprise and point out how they were right. They part ways with the Enterprise in peace.

On the planet, it begins to rain.

Uhura completes her translation of the relic’s musical message. She reports to Una, Pike, and Spock that the comet’s message, recorded hours before Spock’s shuttle mission, foretold the new path the comet would take past the planet as well as the shape it would be after Spock’s fly-by.

After the debrief, Spock approaches Uhura in the corridor and tells her that he believes Starfleet would be fortunate to have her as an officer.

Una and Pike share a drink and discuss fate.

Afterwards, alone, Pike has the computer call up all available information on the Starfleet personnel he will save in the future.