At a university hospital, a pathologist named Tatsuomi Fujimaki, who was unable to rise again, discovered an unknown killer coccus called "Gift" after the suspicious death of a patient. If this coccus invades the body, the patient will die soon. Later, the coccus disappeared completely, and the cause of death could only be diagnosed as acute heart failure. This is a terrible coccus that makes complete crime possible. Can Fujimaki, who accidentally climbed the ladder of power, survive the heroic struggle surrounding the killer coccus? Survival and death, justice and evil, what scene did he see in the end? And who is the real murderer who brought the coccus into the hospital and caused the serial murder case?