In a harsh world that has suffered from a mysterious cataclysm, people, deprived of all the achievements of civilization, are forced to fight not only with cold and hunger, but also with an even more terrible enemy. The Stream is a horde of monsters that, like an eerie river, carves its way through the lands inhabited by the survivors. The only thing that stands between the Stream, which threatens the death of all living things, and the last settlements of people are the Walls, erected by brave defenders and strengthened by their perseverance and fortitude. Over and over again they avert a terrible threat and maintain a fragile peace. But all this can collapse overnight, because even in the face of mortal danger there is no unity among people. Power-hungry rulers, fanatics who blindly believe in their own rightness, cowards and traitors - all of them are slowly but surely eroding what the Flow has not yet been able to destroy. Everything changes the moment a mysterious young man appears in the enclaves, who remembers little about his past, but claims that he saw the place where the Stream originates...