lost-plots-ds9-voy-ent:

Harry Kim has a fit after coming home from the Delta Quadrant and finding out that Nog was promoted from ensign before him. In a sweeping move to save face, Starfleet promotes every single ensign to a junior grade lieutenant. However, due to some programming error (Harry Kim was officially declared dead along with the entire Voyager crew at one point, and somehow was never declared officially un-dead), he does not get the promotion. Harry Kim is still an ensign. Harry Kim is the only remaining ensign in Starfleet. Harry Kim is going to snap. This time, Harry Kim is out for blood.

(inspired by this)