A spying series of sequels with a central hero of Professor Algeras who has discovered a secret weapon. The professor is the target of foreign agents of great powers. The are using every legitimate and unfair means trying to become holders of his scientific discovery. The toughest and ruthless foreign agent, who finally traps Algeras, is the one from iron curtain countries, Milko. Eventually it turns out that Milko, who has been brainwashed, since the Communist Childhood, was the lost and only son of professor Algeras.