The crew of the Artemis has escaped the nightmare of Paradise-1, but at great cost. Parker is gone. Petrova’s past continues to haunt her. Worst of all, Erebus – a timeless entity of pure darkness – has been released from its prison. Now it’s headed for Earth. Petrova must rally her crew for one final mission. Somehow, they must find a way to unite the disparate factions of the solar system – the United Earth Government, the Lunar colonies, and the outer planets – and find a way to stop Erebus. The fate of humanity - and the galaxy - is in their hands.