In season 4, an unknown force is destroying starships and threatening galactic peace. Luckily, the crew of the U.S.S. Cerritos isn't important enough for stuff like that! Instead, Ensigns Mariner, Boimler, Tendi, Rutherford and Provisional Ensign T'Lyn are keeping up with their Starfleet duties, avoiding malevolent computers and getting stuck in a couple caves – all while encountering new and classic aliens along the way.