A tale told in the dark by Neelix is not what it seems.
During a planned power shutdown, the young former Borg drones in Neelix's care wake from regeneration and ask about the sealed area on deck twelve, which they suspect is haunted. To keep them calm, Neelix tells a story from shortly before they came aboard, when Voyager passed through a nebula and accidentally took in a strange creature.
In his tale, systems failed across the ship and crew were hurt, until Janeway realised the creature was trying to communicate. It wanted to return to its nebula, which had broken up, and in its anger it forced the crew to abandon ship and trapped Janeway, until she persuaded it that it needed her and promised to find it a new home. Neelix then suggests he might have made it all up, and the children insist they knew all along. The sixth-season ghost story ends with hints that the tale was true.