While Boimler and Rutherford suspect Mariner is a Section 31 agent, the crew discovers Ferengi harvesting Mugato horns and turns their operation into a sanctuary.
Boimler and Rutherford hear a rumor that Mariner is a spy for Section 31. The Cerritos investigates Mugatos on a world where they should not live and finds Ferengi poachers harvesting their horns. The away team frees the animals, Boimler and Rutherford are separated from the others, and on the ship Freeman compensates the Ferengi buyer after the Cerritos accidentally destroys his ship, only to learn it was a con.
Boimler and Rutherford find Mariner, and together they persuade the Ferengi to convert their business into a Mugato sanctuary. Tendi spends the episode tracking down crew members who are dodging their medical checkups.