A harmless retired woman, a former doctor, is murdered in the entranceway. Two days later, her friend is killed too—she once worked with her as a nurse… The children of the murdered women, journalist Dima Poluyanov and librarian Nadia Mitrofanova, try to understand whether the two deaths are connected. And they learn that not long ago the former chief doctor of the clinic where both women used to work was also killed… All the threads of this strange case lead to St. Petersburg. That is where Dmitry and Nadia go—especially since in their hometown ruthless killers are following them closely. And for now, the only thing that lets the fugitives escape is pure luck. But luck is never permanent. So they must find, first of all, the people behind all this. Otherwise every day for Dmitry and Nadia could be the last…