Course: Oblivion, VOY 5
Extra points for thinking way outside the box on this one, even if it does not make a whole hell of a lot of sense. The mimeographed copies they left of themselves back on the “Demon” planet somehow built a Voyager of their own, set off for the Alpha Quadrant and then, somehow, forgot they were copies. Hey, just go with it.
Of interest, though, is to see how our characters behave in an extreme (and, ultimately, fatal) situation without it really effecting “our” characters. Kinda neat.