In the second book of the novel, the story continues of Professor Sveshnikov’s family and his discovery. In the eighteenth year, the mysterious drug is sought by the Bolsheviks. In our time, it is hunted by adherents of an occult order of seekers of immortality. For everyone else, it remains a secret—Misterium Tremendum. A secret that makes one tremble. A secret that can save, kill, drive you mad, and will never become the property of the powerful.