A small black box holding within it a glimpse of what the future holds.
The Arca Nox was created by Inimicus, god of Fate. It's purpose was to reveal the possible future of any individual that opened it, god or otherwise. Protected by hordes of Kruthiks in Arx Inimicus, the Arca Nox is mysterious to mortals and gods alike.
The Arca Nox is a small black cube, about 6 inches squared. It's sides are smooth and unadorned, although the area immediately around the cube is markedly colder than normal.
The Arca Nox, when touched, reveals hundreds of possible futures for the recipient. It does not reveal which possibility will become reality.