On the train on the way to work, the attention of Dr. Vladimir Knyazev was attracted by a very frightened girl. And despite the fact that the stranger refused to share her fears with him, Knyazev gave her his business card. And the next day an investigator came to him with a message that near the hospital where the doctor works, this girl was hit and killed by a car. Before the incident, the stranger was looking for Knyazev for some reason...