In orbit around Grottonus, Mariner, Boimler, Rutherford, and Tendi discover they’ve all been assigned to the away mission, researching moss in a cave.

Mariner is unimpressed by the cave mission. The others are enjoying themselves until Ransom contacts them to evacuate. Tremors hit, sealing them into the cave.

Mariner gets mad and kicks a rock covered in moss and all the moss in the cave begins to glow.

The moss starts to encroach and eats Tendi’s boot.

They try to brainstorm ways out. When Tendi starts to remind them of the time after the rage virus, Mariner cuts her off to tell her that’s not a cave example. It was a turbolift.

Boimler recounts a cave mission he and Lt. Levy undertook on Kyron 4. Levy insisted they were being trapped and tested by Vendorians. Boimler finally loses his temper and tells Levy his weird conspiracy theory beliefs are why he’s never been promoted.

Boimler’s tirade makes Levy cry. Suddenly, the stalagmites around them transform into Vendorians who declare they have failed the morality test.

Before they can execute Boimler and Levy, the Vendorians are distracted by Levy’s extensive knowledge of Vendorian customs. They find him amusing and Boimler and Levy end up sharing a meal of giant crickets with them.

Boimler tells the team the Vendorians released them and even taught Boimler how to boost his communicator signal with Gammanite.

Boimler’s tricorder detects some trigammanite. Rutherford manages to make some appear on the rocks nearby using Boimler’s pants and Mariner’s deflected phaser blast. He explains he learned to do that when trapped in a cave with Dr. T’Ana and their cave baby.

He recounts his mission with T’Ana to Balkus 9 to gather medicinal ferns. While their guide is showing them the ferns, she is attacked by a graflax. As she is mortally injured, the guide transfers her consciousness to Rutherford by touching his face.

Seconds later, T’Ana delivers a baby version of the guide from Rutherford via c-section. Rutherford faints after being handed the baby.

When he wakes up, he is able to feed the baby rations when T’Ana is unsuccessful. Taking turns watching the baby and exploring the cave system, looking for an exit, they become a family unit.

When the graflax returns, Rutherford turns his tricorder into a translator and they are able to communicate with the beast who is, it turns out, only protecting their own baby who lives in the fern pond.

Back in the current cave, Mariner starts to realign the microcircuitry of the trigammanite with her com badge. She admits she learned to do it from Delta Shift.

It turns out she was leading Delta Shift on an away mission on Glish. Their shuttle was hit with a magnetic anomaly and they crashed into a cave system.

In order to restart the shuttle they need pergium. Mariner spots some but as she moves closer, she suddenly ages. The same things happens to Ensign Caravetos when she walks to her.

Unable to move further, Mariner and Caravetos have it out over the animosity between Delta and Beta Shift. Caravetos points out that Delta Shift does the same jobs as Beta but no one ever gives them credit because everyone’s asleep when Delta Shift is working.

The injured ensign, Asif, is younger than the rest. He tries to make a dash for the pergium but his leg heals wrong and then falls off. Ensign Omadow finds another cache of pergium where the chromotones age his younger. He cracks open his tricorder to separate the pergium they need.

Mariner defends herself when Boimler and Rutherford are incensed by her collegiality with Delta Shift. Everyone is upset that the others had secret friendships and relationships.

Rutherford takes the filtered trigammanite from Mariner and attempts to hail the Cerritos. The moss attacks and pins them all to the wall.

The moss begins talking and decrees that they cannot leave until Tendi tells her story.

Tendi recounts how they all stumbled into a turbolift after celebrating their first adventure together with the rage virus. The turbolift stops and they’re stuck there for two hours, playing a makeshift ball toss game.

Three hours after that, they are playing a guessing game.

Four hours after that, they’re all collapsed in a cuddle puddle. Tendi expresses that she had a great time despite the zombies and having to pee in a corner.

As they’re all relaxing to sleep, Shaxs appears suddenly to save them, scaring them all.

Tendi points out that it doesn’t matter who they hang out with, they’ll always be friends. The moss comments that it’s eaten many visitors but never made a friend. It asks if they can be friends. Tendi says yes, and that they were only there to study it.

The moss releases them and permits them to take their scans. It wants to know they will continue to tell stories. Mariner offers to tell it all her cave stories.

As they start telling another cave story, some stalagmites in the distance transform into Vendorians who deem the Beta Shifters to have passed their test.