In the fifth season, everything seems to be moving as Voyager investigates the birth of a mist. Unfortunately, after the mission's shuttle was caught away in the explosion, a transport accident during the team evacuation caused the doctor's mobile phone to be infected with the seven nanomaterials. The mobile emitter begins to absorb the science laboratory and creates a new unmanned aerial vehicle based on 19th century technology.
Admittedly bleak, [the episode Course: Oblivion] explores concepts of identity, sentience, and legacy with a grim pragmatism that's rare for Voyager, and even for Star Trek. as a whole.