The novel is built on a legend: in the white nights, mermaid corpses from the Neva come ashore and, to death, tickle men passing by. Before the revolution, as is known, a stuffed mermaid caught in the Neva was kept in the Kunstkamera—but unfortunately the exhibit didn’t survive to our days. Still, legends about mermaids living in the Neva exist to this day.
The novel begins when, on the Neva embankment, at the descent near the Troitsky Bridge, they find a homeless man tickled to death. The investigation starts—only to discover that this is already not the first victim in the last year. It is dubbed “The Case of the Tickle Victims.” A half-crazed man comes to the investigator, calling himself a “mermaid expert,” who claims that he has evidence that all the murders are the work of mermaids—and that Petersburg is in danger.
A parallel plot tells about a young man who meets a strange girl, and they begin a love affair. The girl’s former husband is a brilliant surgeon who can perform unique operations, but he is vindictive and cruel—he lays traps for them. The interweaving of many incredible events and riddles keeps the reader constantly tense. In this mystical city, anything is possible: a beauty sleeping in a dresser in lethargic sleep; a centaur running through the streets during the white nights; and, according to the homeless, a spring in the cellar that, if you drink from it, makes a person forget the past—it is said this is only the beginning of the full-flowing River of Oblivion. Everything begins here—in the strange and mystical Petersburg.