It is not for nothing that this gloomy lake, lost in the forests, is called Dark Water. There are no fish splashing in it, no birds flying over it, and, as local residents say, a terrible red-eyed creature is roaming around. No one risks settling in a cursed place. Nina and her little son did not come here of their own free will. They are running from the danger that is hot on their heels, but salvation or even greater troubles await the fugitives at the Dark Water, and even in the mermaid week, when the line between the worlds becomes thinner and the time of dark forces comes?..