Dead waters of the Moscow Sea

Afanasy Karachaev was found dead in his apartment. The official conclusion about death indicates a heart failure, but Lyalya, who loved Karachev, does not believe this conclusion. She turns to a private detective Alexei Kisanov, who is taken up to business. Very soon it becomes clear that Karachaev helped go to the next world. But this was the first and last clear point in this matter: further - solid puzzles. The daughter of Athanasius Karachaeva disappears in the most mysterious way, and the detective is looking for her traces in the dark waters of the Moscow Sea. Versions multiply like molecules in organic chemistry. Inheritance? Business interests? Revenge of an abandoned mistress? Alexei Kisanov never had such a muddy business before! The clue shines only at the very end