The Doctor is called to treat a distressed hologram.
After a promotion party for Tuvok, Tom Paris and B'Elanna Torres begin a relationship. Voyager then receives a call for help from Dejaren, a hologram alone on a ship whose six crewmates have died. Eager to meet another hologram, the Doctor flies over with Torres, who works on stabilising Dejaren's program while he grows nervous and strange. It emerges that Dejaren, who despises living beings, killed the crew himself, and he soon turns on Torres, wounding her badly.
Torres survives thanks to her Klingon physiology, and she destroys Dejaren's matrix with a power cable before she and the Doctor escape. On Voyager, Harry Kim, working with Seven of Nine for the first time, develops a crush on her, and flees when she bluntly suggests they skip romance. The fourth-season episode is a horror story that holds up a dark mirror to the Doctor, a hologram who has learned to care for the people he serves.