New ensign D'Vana Tendi joins the USS Cerritos while Captain Freeman asks Boimler to report on Mariner, and an alien virus brought aboard by Ransom spreads through the crew.
Ensign D'Vana Tendi reports to the USS Cerritos and is shown around by Ensigns Brad Boimler and Beckett Mariner. Captain Carol Freeman quietly asks the by-the-book Boimler to report on Mariner's habit of breaking rules, and on an away mission he watches her hand equipment to local farmers before a farm animal leaves him covered in slime.
Meanwhile Commander Jack Ransom returns with an alien virus that spreads through the ship and makes the crew violent, and Ensign Sam Rutherford fights through the chaos on a date. Chief medical officer T'Ana uses Boimler's slime to produce a cure. Boimler decides not to report Mariner, and the episode reveals that she is secretly Freeman's daughter. Written by series creator Mike McMahan, the premiere introduces the core ensemble.