Omnibus edition (box set) including the complete trilogy This Star Shall Abide (aka Heritage of the Star), Beyond the Tomorrow Mountains, and The Doors of the Universe, which are also available as separate ebooks.
Noren knew that his world was not as it should be--it was wrong that only the Scholars, and their representatives the Technicians, could use metal tools and Machines. It was wrong that only they had access to the mysterious City, which he had always longed to enter. Above all, it was wrong for the Scholars to have sole power over the distribution of knowledge. The High Law imposed these restrictions and many others, though the Prophecy promised that someday knowledge and Machines would be available to everyone. Noren was a heretic. He defied the High Law and had no faith in the Prophecy's fulfillment. But the more he learned of the grim truth about his people's deprivations, the less possible it seemed that their world could ever be changed. It would take more drastic steps than anyone imagined to restore their rightful heritage.
Although these three novels were originally published in hardcover as Young Adult books, the second and third are primarily of interest to older teens and adults; the omnibus edition, first published in 2000, was therefore issued as adult science fiction.
Please note: The cover of this 2013 edition was changed in June 2015. It is not a new edition, as the book itself has not changed.
From the reviews of This Star Shall Abide
Winner of a Christopher Award, given for “affirmation of the highest values of the human spirit.
"Tension-filled, beautiful and haunting." --Commonweal
"Both logically and consistently suspenseful.... This Star will Abide a good deal longer than most here today, gone tomorrow sci-fi." --Kirkus Reviews
From the reviews of Beyond the Tomorrow Mountains
"Engdahl has carefully worked out the social structure and ecology of a scientific society that has been transferred to a planet without metals. What’s more, she wrestles with deeply adult problems of an apparently meaningless universe and of a people’s right to know facts that may destroy everything they hold dear." --Psychology Today
"Introspective readers will identify with Noren and his doubts and sense of despair while the general science fiction buff will appreciate the further experiences of Noren within the credibly developed society on a planet unlike Earth." --Booklist
From the reviews of The Doors of the Universe
"Engdahl can make a reader forget her characters are on another planet, forget that they may not be human in precisely the way the people on this planet are, forget the problems Noren is facing are simply fiction. . . . Humanity, she says, transcends the definitions of outward form and physical location." --Ypsilanti Press
"Although it is the third book of a trilogy, The Doors of the Universe stands powerfully by itself as a quest for survival on a planet that is basically alien to the Six Worlds’ life forms. This is much more than an adventure story. It is one man’s realization of the need for change and his slow acceptance of the responsibility to lead that change. . . . One never gets bored with the story and it haunts the reader long after it is finished." --Journal of Reading