"My Dear Ingleby," the letter from his benefactor read, "I am sorry to learn from my housekeeper that affairs have not been prospering with you. This must be remedied, and at once. There never was such luck as your being in want of employment at this particular moment. I've a billet standing ready and waiting for you; one of the very sort you are fitted for, and one that you will enjoy, unless you have lost your former tastes and inclinations. You have never met Dr. Nikola, but you must do so without delay. I tell you, Ingleby, he is the most wonderful man with whom I have ever been brought in contact, and engaged in an experiment of the most incredible nature. When you have met him, I venture to think you will not doubt that he will carry it through." Dr. Nikola -- the fiend, Nikola. It was a name that chilled Ingleby to the bone.
John Clute writes that "The heart of the series is devoted to the Doctor's convoluted search for a Tibetan process that will resuscitate the dead and ensure immortality in the living, and there are some hints that - unhampered by compunctions, armed with psi powers and blessed with a powerful experimental intellect - he may have reached his goal."