Schoolgirl Christina worked part-time as a nanny. The man, who introduced himself as Viktor Sidnev, asked her to look after the children. He was clearly a resident of the town: he knew the name, phone number, address, nicknames of his neighbors. The girl agreed, and no one saw her alive again. Meanwhile, blondes who look like Christina begin to disappear in the city. And their families receive letters from Vodyanoy - he claims that the girls have become mermaids.