If people were given the ability to predict the course of events!.. Then Aida would not have gone on a date to the Aquarium garden, then Manon, her sister, would not have agreed to meet her new admirer! And the disaster would not have happened, and private detective Alexei Kisanov would not have had to postpone his long-awaited vacation... But the police ask for his help. Two brutal and mysterious murders. The disappearance of a girl drugged with a drug called “truth serum.” And, most importantly, the search for evidence of the criminal’s guilt, which the detective cannot get his hands on! Will the killer go unpunished?..