'''Knights of Forty Islands''' (''Рыцари сорока островов'', Rytsari soroka ostrovov) is a 1990 science fiction novel by the popular Russian author Creator/SergeyLukyanenko. The book is Lukyanenko's first published novel. It's known for a thorough deconstruction of the ChildrenAreInnocent idea.

Dima is a 14-year-old boy used to fighting on the streets of Almaty (Alma-Ata when the book was written), Kazakhstan. One day, he is approached by a strange smiling man with a camera who asks to take the boy's picture for a newspaper article. Dima agrees. However, when the camera flashes, the boy finds himself on a strange island at sea with a castle in the middle. He soon discovers that there are 40 such identical islands, each connected to three others via high and narrow bridges. Every island is populated by 15-18 teens (calling themselves "knights"). They explain that all of them have been kidnapped by an unknown force and told that whichever group manages to conquer all 40 islands gets to go home. Each island is ruled differently. Some rule by democracy, while others have a dictator (either benevolent or brutal). The overall population, as far as boys/girls go, is split 70%/30%, respectively. Some islands are ethnically homogeneous, while others represent a cultural mix. None of the teenagers are older than 18.

For weapons, the mysterious kidnappers have given the kids wooden swords that turn to steel when the wielder feels hatred towards another kid. The teenagers have learned to kill without remorse and ignore wounds while in battle, cover friends, and avenge fallen allies. Dima is no different, and quickly learns to kill or be killed. Using materials found on the islands, the kids have managed to make themselves crude crossbows.

On his island, Dima encounters Inga, a girl he knows from school. From the fact that they remember the last several months differently (she was kidnapped months ago, while he remembers seeing her mere days before being kidnapped himself), they determine that they are actually copies of the original teenagers. After quickly realizing that a single island has no chance to conquer every other island, they propose the formation of a Confederation of islands. Many other islands join peacefully and agree not to attack one another. Those that refuse are taken by force and killed. Dima and several other kids build a boat and try to sail to the islands on the other side of the archipelago to convince the kids there to join the Confederation and speed up the conquest. However, upon return, they find that one of their allies has betrayed them, killed some of the kids on their island, and raped a female friend of theirs.

The Confederation quickly collapses due to mutual distrust, power struggles, and jealousy. Dima and the others find a barricaded room in their castle with skeletons and explosives. From the writing, they discover that the kidnappers have been doing this for many decades, as the remains belong to children kidnapped during WorldWarTwo. As it turns out, these children have also attempted beat the Game by forming a Union of Islands, which collapsed just as the Confederation. In a desperate attempt to keep their island (since many of their defenders have been killed during the betrayal) from being taken by their former allies, the kids use the discovered explosive to blow up one of the bridges, thus allowing them to reinforce the defenses on the other two. However, the kidnappers, annoyed that their rules are being broken, start to freeze the water between the islands in order to allow the neighboring islands to invade by walking on ice.

The kids manage to make their way off the archipelago and discover that it exists in a dome aboard an alien spaceship orbiting Earth. The bird-like aliens called Lotans have been studying human children (specifically, those they determined had a high chance of becoming political or cultural leaders) for many decades in order to understand human psychology and discover human weaknesses in preparation for an invasion. The captured alien explains that the portal to Earth is collapsing due to an explosion in their reactor. Only Dima and Inga go through the portal, with the other kids remaining behind to keep and eye on the aliens and explain everything to the rest of the children. They kiss, but they are interrupted by a group of 13-year-old boys who try have their way with Inga. Using their experience from the islands, Dima and Inga quickly dispatch the teenage gang, although Inga has to stop Dima from dealing a killing blow to one of them.

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!! The novel contains examples of the following tropes:

* AliensAmongUs: The Lotan scout ship has been orbiting Earth for many decades, and members of the crew have been visiting the planet throughout this time using imitator devices to appear human.
* AlienInvasion: According to the captured Lotan, had they managed to successfully send a message to their homeworld, Earth would have already been conquered decades ago.
* ChildrenAreInnocent: Averted. When put in a situation when it's kill or be killed, most of the kids in the novel choose to kill.
* CloningBlues: Dima and Inga are a bit miffed to discover that they're copies.
* CreatorProvincialism: When writing the novel, the author lived in Almaty. Thus, his main character is a teenage boy from that city.
* HigherTechSpecies: A single Lotan scout ship can wipe out all life on Earth. However, there simply aren't enough Lotans aboard to conquer the planet.
* HumansAreBastards: Part of the theme appears to be the impossibility of creating a stable alliance among the various islands. To be fair, most of the members of the Confederation appeared to be willing to maintain the alliance, but there are always those who desire more power or feel themselves superior to those around them.
* InsistentTerminology: The captured Lotan refuses to call his willingness to aid his captors "betrayal". Instead, he insists that he's merely adjusting his behavior. Betrayal is a human concept, not a Lotan one.
* MorphWeapon: The swords used by the teens appear to be made of wood. However, if the wielder feels hatred for the enemy and/or a desire to kill him or her, the weapon turns to steel. As it turns out, the swords were created by the Lotans using their advanced technology.
* NoHoldsBarredBeatdown: Dima and Inga deliver one to a teenage gang after returning to Earth. In fact, Inga has to stop Dima from killing the stupid kids.
* OrphanedSeries: The author started writing the TimeSkip sequel ''Wars of the Forty Islands'' but never finished it.
* RapeAsDrama: One of the girls on Dima's island is gang-raped by their former allies. Also, after returning to Almaty, a group of 13-year-old boys imply that they'd like to get fresh with her.
* RayGun: The Lotans have "emitters".
* TakeAThirdOption: When faced with a possible invasion from one of the three bridges and with not enough defenders to cover all the bridges, Dima and his friends decide to use the WorldWarTwo-era explosives they find in a hidden room to blow up one of the bridges, allowing them to reinforce the other two. This works for a few days, until the aliens begin to freeze the water in lieu of a bridge.
* WeHaveReserves: The captured Lotan suggests using this tactic to force the scout ship's pilot to expend his RayGun's charge. Specifically, he recommends sending the least valuable members of the group and doesn't understand when this earns him a punch to the face.
* WhatIsThisThingYouCallLove: The Lotans have trouble understanding human emotions. The whole experiment is designed to try to map human behavior and psychology, which they see as completely illogical. For example, why does one man give his life to save someone else's child, while another man easily let his own child die?
* YouHaveFailedMe: The crew of any Lotan scout ship faces the death penalty if they go on three hyperjumps without finding anything of note (such as a habitable world to conquer).