The Haunting of Deck Twelve

Neelix, in charge of pacifying the Borg children when lights on the ship flicker and fail, lets his imagination run wild and turns reality into a fantastic but utterly believable story which mesmerizes the children into believing that a ghost actually dwells on Deck Twelve.

As Neelix tells it, months ago an electromagnetic lifeform took possession of the ship, shutting down all life support systems, while trying to communicate with Janeway its need to return to the nebula from which it came. Area by area was cordoned off by an invisible force field, and injected with poisonous gas, while the captain set up an emergency command post in the Engineering Room.