The year is 2147. 50 years have passed since the Echo, a group of rebels led by archivist Adam, overthrew the Guardian, an artificial intelligence that controlled a liberal-totalitarian society. The sacrifice of Adam and his comrades was not in vain. On the ruins of the Harmonious Future, a new society was built based on the principles of democracy, freedom of speech and individuality. Old archives were opened, history was rethought, and the memory of the struggle for freedom became sacred.
The main character is Lina, a 20-year-old granddaughter of one of the members of the original Echo. She grew up in a world where freedom is an inalienable right, but for her it is more a given than a conscious value. She is a talented programmer and is working on the creation of a new generation of AI designed to serve people, not control them.
Suddenly, strange events begin to occur in the seemingly perfect society: vandalism against monuments from the Guardian era, disappearances of people with access to classified archives, the spread of an underground ideology that justifies the Guardian's methods in the name of stability and order.
Lina, trying to understand what is happening, discovers that the seeds of totalitarianism have not been completely destroyed. A secret organization called the Heritage, consisting of descendants of the Harmonious Future elite, seeks to regain lost power and restore control over society. They use the old Guardian methods of information manipulation, surveillance and suppression of dissent, but in an even more sophisticated form.
Lina finds herself drawn into a dangerous game where she will not only have to confront the Heritage, but also rethink the legacy of her ancestors. She understands that freedom is not just a set of rights, but also a constant responsibility that requires vigilance and a willingness to fight for it.
Together with a group of like-minded people - a hacker, a historian and a journalist - Lina creates a new "Echo" to expose the "Heritage" conspiracy and protect their hard-won freedom. They will have to face not only an external enemy, but also the internal contradictions of a new society, where fear of chaos and instability can become fertile ground for the return of totalitarianism. Will the new generation, who have not known the hardships of life under the yoke of the "Guardian", be able to defend their freedom? Or is history doomed to repeat itself, and the shadow of the "Harmonious Future" will once again cover the world?