This fourth novel of Boothby's Dr. Nikola series reveals that Nikola has discovered all of the facts necessary to extend a human being's life. He has studied science and magic secrets of Tibetan monks. He explains: "It has been a long and tedious search, but such labour only makes success the sweeter. The machinery is now prepared; all that remains is to fit the various parts together. In six months' time, if all goes well, I will have a man walking upon this earth who, under certain conditions, shall live a thousand years." To assist him, he hires a destitute young physician, who explains his predicament: "As ill luck would have it, however, I had got into the wrong set, and before I had been two years in the hospital was over head and ears in such a quagmire of debt and difficulties that it looked as if nothing but an absolute miracle co-uld serve to extricate me." That miracle seems to have come to him in the person of Dr. Nikola. The nefarious and wealthy Nikola has purchased a remote castle in the north of England, where the seclusion will allow him and his new assistant and Nikola's deaf-mute malformed Chinese servant to conduct his grand experiment on a human subject.