The ravine in Kolomensky park is the historical place. Many people believe in time portal hidden in it. They believe that sometimes people born centuries ago can come out of this portal. A body of a young woman dressed in vintage clothes is found in the ravine. The witness says that she was murdered by a ghost rider in a black cape. Sounds crazy - but the witness has managed to take a picture of the ghost, and there are traces of hooves around the body - The murder of "the guest from the past" was only a beginning. Crimes go one after another. Investigator Anastasia Vyazemskaya will have to find the mysterious murderer - and she will also find the famous pearl "La Pelegrina" from the collection of the House of Yusupov.