From the back cover:
Almost a century ago, against the better advice of the Hegemony, the Solar Witnesses despatched the Revelation - an antimatter torch ship - on a pilgrimage to the Machine Civilisation Polis in the Altair star system.
IT NEVER CAME BACK. THAT IS, UNTIL NOW.
The Last Witness is a self-contained adventure for River of Heaven, a search and rescue mission out in the black tombs of space far from home.
It uses the default campaign background but with a little work can easily be translated to another setting. While being quite self-contained, it still has potential as the starting point for a campaign.
It comes with six pre-generated player characters.