"The 13th Continuum" by Jennifer Brody
The novel Jennifer Brody is more aimed at a children's audience, but do not take this circumstance too literally: in fact, "The 13th Continuum" is also suitable for adults - of course, provided that these adults love vigorous fiction and are tolerant to young heroes. Perhaps the age of the protagonists (they are from sixteen to twenty) is the only limitation: otherwise, the Brody book is all ages and quite universal.
In some fairly near future Earth, which we know, comes to an End: the surface of the planet burns in the flames of a global cataclysm, and most of humanity perishes. Wise scientists prepared ahead of time for this disaster: they created several arks, the inhabitants of which are to survive the thousand-year decline of the Earth, and then come together and revive human civilization. However, over a thousand years everything can change - which, in essence, is happening.
The connection between the arks is lost and each of them turns into an autonomous microstate, developing according to its own laws. On one of the arks — he waits for a catastrophe in the depths of the world’s ocean — a tough theocracy is established: the Church of the Holy Sea that seized power convinces its flock that humanity has been destroyed for sins, returning to the Surface is impossible and the very thought of it is blasphemy. All who dare to dream of the Earth are thrown overboard, and everything reminiscent of the times until the End (including books, navigation maps, submarines intended for ascent to the surface, and the Lighthouse, which should indicate the place of the upcoming meeting of survivors) are ruthlessly destroyed. However, the millennium, for which the work of all mechanisms of the Ark is designed, comes to an end, the machines fail, the case leaks, and the only thing that can save its inhabitants is an ascent. People who are aware of the danger and are ready to confront it - nothing at all: young Myra, her three friends and her father, the chief engineer of the Ark. In the shortest possible time, they need to recreate the submarine, find the Beacon and raise a rebellion against the clergy in the old, miraculously preserved drawings.
At the same time, the last of the surviving space arks, the militarized ship-state, where emotions are shameful, family and friendships are abolished, and courage, dedication and masterly possession of weapons are considered to be approaching the Earth from the depths of space. A young captain of Aero Wright, a soldier without fear and reproach, yesterday's graduate of the local military academy, in a matter of days will be the first to step onto a planet that his ancestors left a thousand years ago ...
If at that moment you remembered Robert A. Heinlein’s novel "Orphans of the Sky" (in which the lost spacecraft with a feral crew also turns into a frightening and archaic mini-state) or "Lord of the Flies" by William Golding, then In general, your thought is moving in the right direction. Jennifer Brody is an author more than cultural, educated and well-read: she has a history of Harvard diploma, experience in teaching creative writing and participation in Hollywood mega-projects (such as, for example, Jackson's "The Lord of the Rings"). Therefore, with all the deceptive simplicity, in fact, its "The 13th Continuum" is a thing of fine dressing, firmly rooted in tradition and at the same time not deprived of a carefully verified share of novelty. Another thing is that Brody invests all his considerable, cultural, and literary, and even marketing, potential in creating a kind of book version of a cinematic blockbuster (which, by the way, has a good chance of becoming a novel). On the one hand, it is a pity - the author is clearly capable of more. On the other hand, should someone write simply strong, fascinating books designed for ingenuous reading pleasure - such as with a flashlight under the covers.