This story is based on real events that happened several years ago. The series is dedicated to the anniversary of the Federal Security Service. At the center of the events is a brilliant young man named Dmitry Goryunov, widely known in certain circles by the nickname "Chemist." He has created a poison that is a biological weapon of mass destruction. An operational group, led by Captain Mikhail Zuev, carries out an operation to capture the creator of homemade explosives.