Off Armageddon Reef is a science fiction novel written by David Weber and published by Tor Books. It is the first book in the open-ended Safehold series; Weber announced that the next two books in the series will be By Schism Rent Asunder and By Heresies Distressed, expected to be published in 2008.
The original plan for this society was to wait for the immediate danger to pass, rebuild the technological base from records and artifacts left behind, and prepare a force large enough to defeat the Gbaba. However, the mission command is split into two groups, with a radical group, led by an administrator named Langhorne, seeking a total proscription of all advanced technology. This group alters the colonist's memories so they believe they are the first humans and that they were created by a god. The radical leaders create a new religious institution that proscribes advanced technology. The goal is to permanently hold mankind below the level of detection by the Gbaba, allowing mankind to survive but at a Middle Ages technology.
The second group, under the administrator Shan-wei, wishes to preserve advanced technology and concepts, but not to use such knowledge until humanity is ready. In this way, the knowledge would be preserved and available for future generations. Once the human population had recovered, they could gradually ramp up the technology until they were capable of defeating the Gbaba. To this end, the second group establishes a city named Alexandria to house its members and technological information.
The two groups break into open warfare, and Langhorne has the city of Alexandria, and all its inhabitants, destroyed by orbital bombardment. The city and the surrounding land mass is sunk beneath the ocean, creating what the now-superstitious colonists call Armageddon Reef. However, Shein-wei's supporters manage to eliminate most of, if not all of, Langhorn's inner circle, including Langhorn. Shan-wei's group also managed to hide an android, with the personality and memories of a dead female starship tactical officer, deep within a secret mountain base, along with technology, an electronic library and a room full of weapons. When she awakes, the situation is explained and she is given the mission of reversing the plans of the radicals and helping prepare mankind for the inevitable re-encounter with the Gbaba on more favorable terms.
The android travels to the Kingdom of Charis; a relatively advanced region of Safehold with a somewhat free-thinking approach to religion. She then introduces technology that, while not technically proscribed, is more advanced. Events come to a head when the Church organizes an attack on Charis by most of its neighbors, but this is repelled. The book ends about one month after the end of the battle.
In many ways this book is about the human condition at its core, set in a future world of high and low technology. It highlights how the choices individuals make on a day to day basis, as well as the relationships we build define the character and quality of our lives. Classic, and often interesting, themes such as 1) the ability of money and power to corrupt otherwise "good" individuals, 2) the influence of duty and morales in relation to the good of the "many", 3) the power of faith and its tension with orthodoxy, 4) the importance of truth balanced with the need for secrecy, 5) the drive for human innovation and progress, 6) the hopeful human will to survive, even in the face of overwhelming odds, and 7) the tension of whether the "ends" truly justify the "means."
The concept of the technologically superior Gbaba aliens, determined to exterminate all life forms that could be a threat to them, resembles the Achuultani aliens from Weber's earlier novel Mutineers' Moon, the first novel in his Empire From the Ashes trilogy. Furthermore, the third novel in that trilogy, Heirs of Empire, contains a plot where a small group of people with high technology use their knowledge of military weapons and tactics to assist a group of humans living on a world of low technology. This resembles how on the planet Safehold the character Merlin assists the Charisians in their struggle with the Church and it allies.