From the introduction [spoiler warning]:
This adventure follows the events detailed in Forsaken Bounty. After facing off against malign influence of the Psycharus Worm, the Explorers find themselves in possession of both the Emperor’s Bounty and the fell Halo Device that led to its demise. Unfortunately for them, their actions have had more far reaching consequences than they could imagine, and in defeating the thralls of the Worm they have stirred up dark forces and ancient alien powers. In this adventure, the Explorers will learn of the true power of the Worm and catch a terrifying glimpse into the legacy of its creators. Their vessel and crew will be subverted by the power of a terrible xenos race known as the Yu’vath—an evil thought by most to have been long since extinguished from the galaxy—and they will be drawn into an ancient trap from which they must find a way to escape or become lost forever.
You do not need a copy of Rogue Trader to play this adventure. It can be run using the characters and rules presented in the Forsaken Bounty booklet (available for download from the Fantasy Flight website). However if you do possess a copy of the Rogue Trader rulebook, guidelines have been presented to allow the GM to expand on certain encounters and challenges—adding such things as space battles and alternative enemies.