By way of a re-cap:
Passengers to Sentience - Data detective Ben meets Lori in a body-swap encounter, only to be kidnapped on the return journey. Their quest for freedom is thwarted at every turn. Will they ever get the break they deserve and find their way home?
Passengers to Zeta Nine - Raife and Dr. Nancy Zing's craft parks itself in orbit above a lush planet apparently ripe for colonisation. Everything should proceed with predictable smoothness but what they get is one surprise after another, some pleasant, some not so pleasant.
Passengers: Revelations - Ben and Lori, Raife and Nancy, and a few other characters embark on separate adventures which overlap each other amidst the plans of criminal master-mind, Blis. Unexpected events overtake each of them in different ways, leading to the as yet untold fourth part of this story.
Although each novel is part of a developing story gradually including more characters, each book is also a stand alone story.
Produced on thick, cream paper, Passengers: Revelations has a somewhat higher word-count than Passengers to Sentience and Passengers to Zeta Nine.