A lonely old lady is found dead in her apartment in the high-rise building on Kotelnitcheskaya embankment. This woman used to be the famous soviet ballet prima. Nothing was stolen from the apartment, the door wasn't broken, but there is a cry for help written by fingers on the window glass. Investigator Anastasia Vyazemskaya is looking for a motive of this strange crime when another person becomes a victim of the mysterious murderer. Very soon she finds out that something strange is happening in famous Moscow high-risers. The buildings called "Seven sisters" are connected mysteriously, and Anastasia will have to unravel this mystery.